Part 2: new processors, new technologies

Less than a week after the publication of the previous article on energy management technologies for modern processors, our test lab got an Intel Pentium 4 processor, and a week later - Intel Xeon with a new revision of Prescott and Nocona cores, respectively (stepping E0, signature CPUID = 0F41h). The first showed, at first glance, very interesting behavior when in idle mode (which will be discussed below). The reason for this phenomenon was found out pretty soon - it turned out that the new revision of the Prescott core, along with the Execute Disable (XD bit) and Thermal Monitor 2 (TM2) technologies, supports new technology Enhanced Halt State (also known as C1E). A similar operating mode, along with the Enhanced SpeedStep (DBS) server technology, is implemented in the new revision of the Nocona core. This article is devoted to the study of C1E technology, as well as the thermal monitoring mechanism # 2, implemented in Pentium 4 / Xeon processors with the release of a new revision of Prescott / Nocona cores.

Testbed configuration

Booth # 1

• Processor: Intel Pentium 4 3.6 GHz (Prescott core, CPUID 0F41h)
• Chipset: Intel 925XE
• Motherboard: Intel D925XECV2 BIOS version 1817 dated 10/12/2004
• Memory: 2x256 MB Samsung DDR2-533
• Video: Leadtek PX350 TDH, NVIDIA PCX5900

Booth # 2

• Processors: 2x Intel Xeon 3.6 GHz (Nocona core, CPUID 0F41h)
• Chipset: Intel E7520
• Motherboard: Intel Server Board SE7250AF2, BIOS version 2023 dated 08/05/2004
• Memory: 4x1024 MB Patriot Registered DDR2-533
• Video: ATI RAGE XL PCI (Integrated)
• HDD: WD Raptor WD360, SATA, 10000 rpm, 36GB

Software

• version 1.3beta2
• version 2.0.11.46
• version 1.01

Enhanced Halt State technology

What is the possible alternative? It can be assumed that, since some processor units (for example, bus arbiters, asynchronous prefetchers, etc.), most likely, cannot easily switch between different operating speeds, Intel engineers, most likely, "divided" the processor core into several independently clocked components (either due to several PLLs, or due to frequency dividers that convert the reference clock frequency). Some of these components always operates at full frequency (this part also includes the Time Stamp Counter, on the readings of which the generally accepted method of measuring the processor clock frequency is based), while the rest of the parts (execution modules) may clocked at a lower frequency. At the same time, however, it is not entirely clear why Intel engineers decided to clock the TSC at full frequency, while the processor performance monitoring counters (PMC) operate at a "reduced" frequency?

Possible explanations of this fact, as well as the choice between the presented points of view, will be left to the reader. For our part, we note that in the course of our research we were unable to find any experimental evidence in favor of the second, more "official" hypothesis. Of course we don't have explicit evidence and in favor of our point of view, except that it does not contradict experimental facts. Therefore, we will deal with "proof by contradiction." Among the main objections to our point of view, one can outline, firstly, the incorrectness of the method for determining the processor frequency, and secondly, in fact, our statement that Pentium 4 and Xeon processors can operate at full frequency with a reduced supply voltage (in modes TM2, DBS and C1E).

Let's start with the first statement. The correctness of determining the actual frequency of the processor is beyond doubt - this method is used all without exception, system utilities (CPU-Z, WCPUID), finally, the operating system itself, as well as ... Intel Processor Identification Utility! The screenshot below was taken on a 3.6GHz Intel Xeon processor with Enhanced SpeedStep enabled.

We believe that the picture is self-explanatory: the processor frequency was measured by the TSC utility (3.6 GHz), and the system bus frequency was measured by simply dividing it by the current "multiplier" 14x, which leads to an incorrect final value of 1028 MHz and an eloquent inscription "Overclocked!"... So, if Intel utilities are using the “wrong” method, what should be considered the “right” method? Applying formulas of the form

FSB_freq = TSC_freq / Startup_FID
CPU_freq = FSB_freq * Current_FID,

those. banal multiplication of the system bus frequency of the processor by the current "multiplication factor"? (This is the method, most likely, was used during the demonstration of DBS technology at IDF 2004 Russia) Sorry, but this is no longer genuine dimension and natural fit, wishful thinking. Moreover, this method will obviously not be universal, i.e. unusable for any x86 compatible processor.

Watch what happens: the processor is “confident” that it is still operating under normal conditions, and therefore dynamically manages its supply voltage when idle thanks to C1E technology. While its real frequency - both true and effective - is equal to 3.74 GHz. It turns out that Pentium 4 and Xeon processors can actually operate at full frequency with reduced supply voltage if they are in idle mode (C1 / C1E).

Thus, the above facts, although they do not explicitly confirm, but additionally support our conclusion about a unified basis for the implementation of performance and power consumption management functions in Intel Pentium 4 and Xeon processors.

In the assortment of AMD and Intel for desktops, there are always energy-efficient processors, but few people think about how much they save electricity. Manufacturers usually reduce power consumption by introducing reduced frequency profiles into the CPU algorithm. For example, instead of the 3.8-4.4 GHz range, the processor develops a frequency from 2.3 to 4.4 GHz. Thanks to this, in operation at partial or minimum load, power consumption is reduced from an average of 90-120 watts to 35-35 watts. We will try to find out how much this affects the overall consumption.

Energy Efficient Processors: How High is the Power Consumption?

is there any point in energy efficient processors?

• Energy efficient processors can be recognized by their product names. In the case of CPU production Intel the abbreviation “S” or “T” is used, AMD labels such processors with a small letter “e”.
• The Thermal Design Power (TDP) value for energy efficient processors is in the region of 35-45 W. For conventional processors, this value is usually in the range from 65 to 95 watts.

Energy efficient processors: do they really make sense?

• In practice, the low power consumption of energy efficient processors is not suitable for every purpose. Since in most cases these processors have two rather than four cores, they may take a little longer to complete tasks.
• However, this will only be a real problem with multithreading. For the average PC user, Multithreading is of little interest. For this reason, not too much overpayment for an energy efficient processor will be justified in most cases.
• In addition to saving directly on electricity, you also get a slightly quieter cooling fan and less heat generated. In the case of very compact systems, this factor can be extremely important.
• In addition, for gaming, as they say, from time to time, energy-efficient processors, thanks to the appropriate graphics cards, can also be quite suitable. However, keep in mind that power-efficient CPUs can be your weak point in multiplayer mode due to multithreading issues.
• On average, a PC consumes from 100 to 350 watts (system unit), and the processor's share is no more than 100-120 watts. Therefore, the use of an energy efficient CPU leads to savings of 40-60 watts, which is not so much against the background of the total energy used.
• The purchase of an energy efficient processor is relevant for miniITX systems. Such cases use motherboards with a low power supply system. Therefore, by installing a CPU with reduced power consumption, you will fit a compact cooling system into the case and get rid of excessive heat generation.

Introduction Sandy Bridge processors have earned the right to be called the revolutionary development of the Core microarchitecture not only with their increased speed - at the same time they also offered users a higher specific performance in terms of each watt of energy expended. This immediately has a beneficial effect on the battery life of modern mobile computers, bringing the dream of notebooks that do not require recharging all day long to come true. Moreover, it is the Sandy Bridge microarchitecture that should give life to a new class of portable devices - ultrabooks, which will combine the main advantages of tablets and classic laptops: compactness, lightness, versatility and low cost. In other words, the influence of the modern processor microarchitecture on the development of the mobile market was more than noticeable.

But the energy efficiency of Sandy Bridge is reflected not only in the properties of today's laptops. It also played a role in the desktop segment. So, it was thanks to her that Intel introduced a whole large family of processors for desktop systems with reduced power consumption. These processors were able to get registered in a separate class of home computers called "Lifestyle PC" and combining HTPCs, compact and quiet home systems, all-in-ones and so on. Of course, we cannot say that before the release of Sandy Bridge Intel could not offer users anything like this, but earlier desktop processors with low heat dissipation were represented only by exceptional and rare models. Now the situation has changed dramatically: in parallel with conventional desktop 95- and 65-watt CPUs, Intel's product range has expanded due to two full-fledged processor lines with lower thermal packs of 65 and 45/35 W. Moreover, these processors, like their "normal" counterparts, have a quite acceptable integrated graphics core of the Intel HD Graphics series, which in many economical systems allows you to do without a discrete graphics card.

Of course, economical models are somewhat inferior in performance to conventional processors, which do not focus on low power consumption and heat dissipation. But, nevertheless, it is impossible to characterize their performance with any offensive epithet, since by modern standards they are quite productive. The following table shows how the nominal clock frequencies of current processors are distributed in conventional and economy lines.

Frequencies of conventional processors are shown against a pink background. Against a light green background, the frequencies of the economical S-series processors are indicated, which have a typical heat dissipation reduced to 65 W. The blue background highlights the frequencies of the T-series, which are among the most energy efficient models - with a thermal package of 35 or 45 W.

Roughly speaking, the S-Series offers economical versions of the most powerful Sandy Bridge processors and delivers a 30% reduction in heat dissipation at the expense of a 20% reduction in clock speed. The T-series provides more radical savings, but at the same time, the clock frequency reduction relative to conventional models can be up to 25-30%.

In this article, we decided to pay attention to the most interesting line of economical processors - the T series. Their calculated heat dissipation is so low that it allows using such CPUs without any tricks in the smallest Mini-ITX cases and assembling quiet fanless systems on their basis. Since the video core of the Intel HD Graphics series integrated into these processors in many cases makes it possible to do without an external graphics card, and the power consumption of the chipset required for Sandy Bridge is only 6.1 W, then complete system with a T-series processor can easily get along with a 60-watt power supply, in terms of energy parameters it comes close to mobile platforms... However, the question arises - is it not too significant sacrifices in terms of performance will have to be made by the users focused on economy? It is these doubts that we will try to dispel with this study.

Sandy Bridge processors, T-series

Any energy efficient Intel processors gets very in a simple way... The manufacturing process makes no distinction between standard Sandy Bridge semiconductor chips and chips for lower power and lower heat dissipation processors. Only at the final stage of production, processors, which subsequently should be distinguished by lower heat dissipation and power consumption, are assigned lower clock frequencies and, in addition, a reduced supply voltage is set for them. These two elementary actions are quite enough to separate the second generation Core processors into different groups, in which the typical heat dissipation differs significantly.

Although the described approach to creating energy-efficient CPUs seems primitive, it not only works great with Sandy Bridge semiconductor crystals, but also allows them to keep their costs low. It is because of this that the prices of T-series processors are only slightly higher than those of conventional models. So Intel does not put any economic obstacles in the way of their distribution, which further encourages their widespread distribution.

Intel currently has four T-series processors with typical heat dissipation reduced to 45W or 35W. All these processors belong to different lines and differ not only in clock frequency. They offer a different number of cores and a different set of supported technologies. In other words, their variety is quite enough to be able to choose the most suitable option, based on the required level of performance and functionality.

Let's take a closer look at the representatives of the T series.

Core i5-2500T

The Core i5-2500T is the only quad-core in the T-series. Obviously, squeezing this processor into such a narrow power consumption frame was not easy, the typical heat dissipation for it was set at 45 W, while all other representatives of the T-series have a TDP of 35 W. Therefore, the fact that the nominal frequency of this model is only 2.3 GHz, that is, below the frequency of a full-fledged Core i5-2500 by a whole gigahertz, does not cause any surprise.

However, the concept of the nominal clock speed for the Core i5-2500T is very relative. This processor supports Turbo Boost technology, which in this case works quite aggressively. The maximum frequencies to which the Core i5-2500T can auto-overclock when loaded on a different number of cores are given in the table. For comparison, in the same table, we have placed data on the operation of Turbo Boost technology in conventional Core i5 processors.

As you can see, the comparatively low frequency is inherent in the Core i5-2500T only when loaded with three or four cores. In a state of less intensive load, this processor is capable of significant auto-overclocking, reaching one gigahertz. As a result, an economical processor catches up with its full-fledged counterparts and, with the passivity of two or three cores, is capable of delivering even more high productivity than a Core i5-2300 or Core i5-2310.

The voltage value shown in the above screenshot of CPU-Z cannot be trusted. In fact, our Core i5-2500T was powered by 1.080 volts, which is about 0.1 volts less than typical quad-core Core i5 processors. So the efficiency of the Core i5-2500T stems not only from its trimmed clock speeds, but also from its operation at reduced voltage.

Particularly curious in this regard are the characteristics of the graphics core built into the Core i5-2500T. In this case, it is Intel HD Graphics 2000 with six execution units, which is present in most second generation Core processors for desktops. However, the frequency of this core in the Core i5-2500T can vary much wider than that of other processors. The nominal value is 650 MHz (versus the usual 850 MHz), but "graphic" Turbo Boost can increase this frequency to 1.25 GHz (versus 1.1 GHz in the standard version). In other words, if the load on the graphics is not accompanied by the full employment of processor cores, then the Core i5-2500T will surpass even the 95-watt Core i5-2500 in 3D performance.

Core i5-2390T

Although Intel has classified the Core i5-2390T as part of the Core i5 family, this processor is fundamentally different from the rest of this family. While all other Core i5s are quad-core CPUs, the Core i5-2390T is a dual-core processor. However, it also would not fully fit into the Core i3 family, since it has support for Turbo Boost technology, which is inherent only in the Core i5 and Core i7 lines. In other words, it would be most correct to single out the CPU in question into a non-existent "intermediate" Core i4 group, but, obviously, Intel did not want to confuse the already complicated nomenclature for the sake of one product.

Similar to the Core i3 processors, the Core i5-2390T supports Hyper-Threading technology, that is, in the operating system it looks like a quad-core, just like the "real" Core i5. However, Hyper-Threading cannot be an alternative to physical processor cores, so their absence has to be compensated for by clock frequencies. For example, the nominal frequency of the Core i5-2390T is 2.7 GHz, while the frequency of the Core i5-2500T is 400 MHz lower.

The Core i5-2390T and Turbo Boost technology are quite energetic. Let's compare the clocks of the 35W Core i5-2390T with those of the other non-economy series Sandy Bridge dual cores with Hyper-Threading Technology, which have a TDP of 65W.

Despite the fact that the nominal clock speed of the Core i5-2390T is significantly lower than the frequency of the Core i3 series processors, in real work it can overclock and surpass them in speed, because the other dual-core Sandy Bridge technology does not support Turbo Boost at all. However, being implemented in an economical dual-core processor, this technology is clearly not formal, it can significantly increase the frequency of this CPU.

The operating voltage of the Core i5-2390T turned out to be 1.092 V, and this is higher than the voltage of the Core i5-2500T. But, nevertheless, due to the reduced number of processing cores, the dual-core processor has a lower calculated typical heat dissipation of 35 watts.

As for the graphics core, in this case Intel HD Graphics 2000 is built into the processor with a nominal frequency of 650 MHz lower than that of conventional CPUs. However, the Turbo Boost technology for the GPU compensates for this disadvantage - graphics auto-overclocking is provided up to 1.1 GHz, that is, to the same level to which the graphics core in a 95-watt Core i5 can autonomously overclock. At the same time, this means that in terms of graphics speed, the Core i5-2390T is inferior to its quad-core economical counterpart, the Core i5-2500T.

Core i3-2100T

The Core i3-2100T has no special secrets. This is a regular dual-core Core i3 with support for Hyper-Threading technology, but without Turbo Boost technology, which has a reduced clock frequency for the sake of lower heat generation and power consumption. However, the magnitude of this decrease is not so significant. Even regular Core i3 processors are quite economical, so in order for the Core i3-2100T to fit into the 35-watt thermal package, Intel had to slow down its frequency relative to the 65-watt Core i3-2100 by only 600 MHz.

It should be noted that in this case it was possible to get by with less deceleration. For example, the Core i5-2390T, similar in number of cores and threads, successfully operates at a higher clock frequency without going beyond the 35-watt frame. So just 2.5 GHz Core i3-2100T frequency is partly a marketing move aimed at ensuring that there is a noticeable performance gap between the Core i5-2390T and the Core i3-2100T. Moreover, the operating voltage of the Core i3-2100T and Core i5-2390T is the same and is 1.092 V.

The graphics core in the Core i3-2100T does not differ from the graphics in the Core i5-2390T. Used Intel HD Graphics 2000 with six executive units and frequency from 650 MHz to 1.1 GHz in auto overclocking mode.

Delving deeper into the study of the differences between the Core i3-2100T and the Core i5-2390T, it should be noted that the younger series processor lacks support for the AES instruction set. But this is a feature of all Core i3s that has nothing to do with energy conservation.

Pentium G620T

Closing the four processors with reduced heat dissipation is the Pentium series processor. This is Pentium G620T - a budget dual-core CPU without Hyper-Threading and without Turbo Boost support. It differs from the usual Pentium G620 with a 400 MHz clock frequency and a calculated heat dissipation reduced from 65 to 35 W.

As we saw in previous tests, even standard Pentium processors do not differ too much from the Core i3-2100T in terms of their consumption. So the creation of a 35-watt model in the ranks of this family is not so much an improvement. However, the power supply voltage of an economical budget CPU turned out to be reduced to 1.056 V, which is about 0.05 V lower than the voltage used by conventional Pentiums.

The graphics core of the Pentium G620T is Intel HD Graphics. Compared to the graphics built into the second generation Core processors, it lacks support for Quick Sync technology, and this is a feature of any Pentium. What distinguishes the energy-efficient model is the operating frequencies of this GPU. The nominal value is 650 MHz, not 850 MHz. However, the maximum frequency during auto-overclocking reaches 1.1 GHz, that is, there are no differences from 65-watt Pentiums in this parameter.

Like the rest of the Pentium line, the energy efficient model lacks support for AES and AVX instructions. Also, the specifications of this processor do not include support for DDR3-1333 SDRAM, so in practice this CPU has to be used with slower memory.

How we tested

When testing the low-power T-series processors, we decided to compare its performance with the speed of conventional LGA1155 processors. This will answer the question posed at the very beginning - do 45- and 35-watt CPUs lose much in speed in comparison with typical Sandy Bridge. Therefore, along with the four processors with the T suffix in the name, Core i5-2310, Core i3-2120, Core i3-2100, Pentium G850 and Pentium G620 took part in the tests.

When testing energy-efficient Sandy Bridges, we tried to recreate their typical "habitat", and therefore refused to use an external high-performance video card, preferring it to the graphics core built into the processor. As a basis for the test platform, we chose the popular Mini-ITX motherboard on the Intel H61 chipset, ASUS P8H61-I.

As a result, the composition of the test systems included the following hardware and software components:

Processors:

Inlel Core i5-2500T (Sandy Bridge, 4 cores, 2.3 GHz, 6 MB L3, 45 W);
Inlel Core i5-2390T (Sandy Bridge, 2 cores, 2.7 GHz, 3 MB L3, 35 W);
Inlel Core i5-2310 (Sandy Bridge, 4 cores, 2.9 GHz, 6 MB L3, 95 W);
Intel Core i3-2120 (Sandy Bridge, 2 cores, 3.3 GHz, 3 MB L3, 65 W);
Intel Core i3-2100 (Sandy Bridge, 2 cores, 3.1 GHz, 3 MB L3, 65 W);
Intel Core i3-2100T (Sandy Bridge, 2 cores, 2.5 GHz, 3 MB L3, 35 W);
Intel Pentium G850 (Sandy Bridge, 2 cores, 2.9 GHz, 3 MB L3, 65 W);
Intel Pentium G620 (Sandy Bridge, 2 cores, 2.6 GHz, 3 MB L3, 65 W);
Intel Pentium G620T (Sandy Bridge, 2 cores, 2.2 GHz, 3 MB L3, 35 W).

CPU cooler: stock Intel cooler.
Motherboard: ASUS P8H61-I (LGA1155, Intel H61, Mini-ITX).
Memory - 2 x 2 GB DDR3 SDRAM (Kingston KHX1600C8D3K2 / 4GX):

DDR3-1067 7-7-7-21 with Pentium G620 and Pentium G620T processor;
DDR3-1333 9-9-9-27 when using other processors.

Hard disk: Kingston SNVP325-S2 / 128GB.
Power supply: Tagan TG880-U33II (880 W).
Operating system: Microsoft Windows 7 SP1 Ultimate x64.
Drivers:

Intel Chipset Driver 9.2.0.1030;
Intel HD Graphics Driver 15.22.1.2361;
Intel Management Engine Driver 7.1.10.1065;
Intel Rapid Storage Technology 10.5.0.1027.

Performance

Overall performance

To assess the performance of processors in common tasks, we traditionally use the Bapco SYSmark 2012 test, which simulates the user's work in common modern office programs and applications for creating and processing digital content... The idea of ​​the test is very simple: it produces a single metric that characterizes the weighted average speed of a computer.

The SYSmark 2012 results are quite expected. The Core i5-2500T loses to the Core i5-2310 by about 9%, the Core i3-2100T is inferior to its 65-watt counterpart by 17%, and the Pentium G620T is 13% behind the regular Pentium G620. At the same time, the 45-watt quad-core Core i5-2500T outperforms all 65-watt dual-core processors, and the same can be said about the dual-core Core i5-2390T, which is well supported by its Turbo Boost technology. The slower dual-core economical processor Core i3-2100T in terms of performance is on a par with the Pentium G850, but the Pentium 620T turns out to be a completely unhurried product, which, obviously, can only compete with the representatives of the Celeron series in LGA1155 that have not yet been released.

A deeper understanding of the SYSmark 2012 results can provide insight into the performance scores obtained in various system use cases. The Office Productivity script simulates a typical office work: preparing texts, processing spreadsheets, working with by e-mail and visiting Internet sites. The script uses the following set of applications: ABBYY FineReader Pro 10.0, Adobe Acrobat Pro 9, Adobe flash Player 10.1, Microsoft Excel 2010, Microsoft Internet Explorer 9, Microsoft Outlook 2010, Microsoft PowerPoint 2010, Microsoft Word 2010 and WinZip Pro 14.5.

The Media Creation scenario simulates the creation of a commercial using pre-shot digital images and video. For this purpose, popular packages from Adobe are used: Photoshop CS5 Extended, Premiere Pro CS5 and After Effects CS5.

Web Development is a scenario within which the creation of a website is modeled. Applications used: Adobe photoshop CS5 Extended, Adobe Premiere Pro CS5, Adobe Dreamweaver CS5, Mozilla Firefox 3.6.8, and Microsoft Internet Explorer 9.

Data / Financial Analysis Scenario is dedicated to statistical analysis and forecasting of market trends that are performed in Microsoft Excel 2010.

3D Modeling Script is all about creating 3D objects and rendering static and dynamic scenes using Adobe Photoshop CS5 Extended, Autodesk 3ds Max 2011, Autodesk AutoCAD 2011 and Google SketchUp Pro 8.

The last script, System Management, performs backups and installs software and updates. Several different versions of Mozilla Firefox Installer and WinZip Pro 14.5 are involved here.

Application performance

To measure the speed of processors when compressing information, we use the WinRAR archiver, with which we archive the folder with the maximum compression ratio. various files with a total volume of 1.4 GB.

We measure performance in Adobe Photoshop using our own benchmark, which is a creatively reworked Retouch Artists Photoshop Speed ​​Test including typical processing of four 10-megapixel images taken with a digital camera.

When testing the audio transcoding speed, the Apple iTunes utility is used, with the help of which the contents of a CD-disc are converted to AAC format. Note that a characteristic feature of this program is the ability to use only a couple of processor cores.

To measure the speed of video transcoding into H.264 format, the x264 HD test is used, which is based on measuring the processing time of the original MPEG-2 video recorded in 720p resolution with a 4 Mbps stream. It should be noted that the results of this test are of great practical importance, since the x264 codec used in it underlies numerous popular transcoding utilities, for example, HandBrake, MeGUI, VirtualDub, etc.

Speed ​​testing final rendering in Maxon Cinema 4D is performed using the specialized Cinebench benchmark.

Looking at the diagrams above, you can once again repeat everything that has already been said in relation to the SYSmark 2011 results. In general, the Core i5-2500T and Core i5-2390T seem to be very productive, but at the same time economical processors. In most cases, their speed is in the range between the speed of the quad-core 95-watt Core i5 and dual-core 65-watt Core i3. Therefore, it is these processors that are of primary interest if you want to build a powerful and economical system.

As for the performance of the Core i3-2100T and Pentium G620T, they should first of all be considered from the position of a favorable price. Frankly speaking, they show low results, but no one promised that inexpensive solutions would shine with dizzying performance.

In addition to the tests carried out, to check the operation Intel technology With Quick Sync, we measured the transcoding speed of a 3GB 1080p H.264 movie (which was a 40-minute episode of the popular TV series) downsampled for viewing on iPhone 4. For transcoding, we used the popular commercial Cyberlink MediaEspresso 6.5 utility, which supports the technology Quick Sync.

Here the results are divided into two large groups. The first includes the Core i5 and Core i3 processors, in which there is support for the Quick Sync technology, the second is the Pentium, which lacks this technology. The difference in transcoding time for these groups is approximately fourfold. The second factor that can affect the speed of MediaEspresso is the frequency of the graphics core. That is why the economical Core i5-2500T unexpectedly takes the lead in this test. Its graphics core is capable of dynamically overclocking up to 1.25 GHz, while in all other processors the maximum graphics frequency is limited to 1.1 GHz.

Gaming performance

The 3D gaming benchmark group opens with 3DMark Vantage, which was used with the Entry profile.

The score in the popular 3DMark Vantage benchmark is primarily affected by graphics performance. Therefore, the first place here is occupied by the Core i5-2500T, in which the Intel HD Graphics 2000 core operates at a higher frequency than the rest of the test participants. The rest of the processors are located in a relatively dense group, in which the differences in readings are determined primarily by their computing capabilities. At the same time, we note that, in contrast to the results in SYSMark 2012 and in applications, the Core i5-2390T looks somewhat disappointing in 3DMark Vantage. Here its speed drops to the level of the Core i3-2100 due to the fact that it is a dual-core processor, although the manufacturer attributes it to the Core i5 series.

To study the performance in real games, we selected Far Cry 2, Dirt 3 and Starcraft 2. These games are characterized by the fact that they show an acceptable level of performance on the integrated graphics core Intel HD Graphics 2000. However, to achieve it, we ran the tests in 1280x800 mode, and the quality settings were set to Low.

And again, for obvious reasons, the Core i5-2500T is in the lead. It would seem that the HD Graphics 2000 graphics core of this processor can only be overclocked a little more than in other CPUs, but even this is enough for quite tangible gaming superiority. The rest of the Core i5 and Core i3 processors are in a tight group on the diagrams. Only the Core i3-2100T lagged somewhat behind in Starcraft 2. Like the younger Pentium CPUs, it clearly lacks the computational performance to fully support the graphics in this highly processor-dependent game.

Energy consumption

Testing has shown that T-series processors are significantly inferior to "conventional" modifications in terms of computing performance. This is a side effect of reducing power consumption, which is achieved, among other things, by reducing those frequencies. However, until now, we have talked about the low level of consumption only in a theoretical way, based on the official specifications. Now is the time to evaluate practical energy efficiency.

The graphs below show two energy consumption values. The first is the total system consumption (without a monitor), which is the sum of the energy consumption of all components involved in the system. The second is the consumption of only one processor through a dedicated 12-volt power line. In both cases, the efficiency of the power supply is not taken into account, since our measuring equipment is installed after the power supply and records the voltages and currents entering the system via 12-, 5- and 3.3-volt lines. During the measurements, the load on the processors was created by the 64-bit version of the LinX 0.6.4 utility. The FurMark 1.9.1 utility was used to load the graphics cores. In addition, to correctly estimate idle power consumption, we have activated all available energy-saving technologies, as well as Turbo Boost technology.

The differences in consumption between conventional and low-power processors are already noticeable when they are idle. 45- and 35-watt processor modifications, even when idle, can provide a total savings of 1-2 watts, which is achieved through lower idle processor voltage when Enhanced Intel Speedstep technology is activated.

A very interesting picture is observed when the load is only on one computational core of the processor. Here, the 45- and 35-watt Core i5-2500T and Core i5-2390T processors do not show their economy in any way. The reason for this lies in their very aggressive implementation of the Turbo Boost technology. With part-time employment, they briskly lift up the clock frequency, choosing the entire resource of the heat pack and coming close in speed to their 95- and 65-watt counterparts, which do not dare to overclock equally decisively. As for the Core i3-2100T and Pentium G620T, they do not have Turbo Boost technology, and therefore their consumption turns out to be several watts lower than that of the 65-watt Core i3-2100 and Pentium G620.

Interesting results are obtained even with the maximum load on the processing power of the processors. In general, systems built using representatives of the T-series demonstrate significantly lower consumption than platforms using standard processors of the same class. But, nevertheless, in the practical indicators of consumption, you can notice some funny inconsistencies. For example, the Core i5-2500T processor, which has a maximum calculated heat dissipation of 45 W, turns out to be more power hungry than the Core i3-2120, whose TDP is 20 W higher. It is clear that this is due to the different number of cores, but the fact remains. Likewise, the Core i5-2390T has higher power consumption than the Pentium G850.

All this suggests that T-series processors in real life are not always more economical than their "normal" counterparts. They are better in terms of specific performance per watt of energy consumed, but when comparing the absolute values ​​of power consumption, they can lose to significantly slower CPUs with a higher declared TDP level. And this must be borne in mind.

When testing consumption with graphics load, the results do not give any particular surprises. The Intel HD Graphics 2000 graphics core is much less power hungry than the computing cores, so the manufacturer did not particularly optimize this part of the CPU. The result of this approach is a slight discrepancy in the actually measured consumption in this case. Only the Core i5-2500T stands out, in which the graphics core is overclocked to a higher frequency than in all other cases.

A similar picture is observed when using processors as the basis of a media center. The load in the form of decoding high-definition video content results in slightly different power consumption for systems with processors with 95-, 65-, 45- and 35W TPUs.

conclusions

The microarchitecture of Sandy Bridge is striking in its versatility. We have admired more than once how powerful processors built on it can be, and today we are convinced that it is equally well suited for creating attractive proposals for quiet, small-sized and economical systems. However, the economical T-series processors based on Sandy Bridge have revealed a number of peculiar features that are not reflected in the specifications in any way and can somewhat change the general impression of these products.

Let's take a look at the power consumption. Despite the fact that T-series processors have half the TDP compared to conventional processors, this does not mean that in reality they consume half as much. Firstly, economical processors get close enough to the border of their thermal package, while CPUs that are not burdened by any obligations in terms of maximum heat release often demonstrate much less power consumption and heat release than indicated in the specification. Therefore, in reality, the difference in practical consumption between T and non-T processors of the same class is not doubled. Secondly, a serious difference in consumption between economical and conventional processors manifests itself in only a small number of scenarios, while in most situations they generally demonstrate very similar energy appetites. In fact, the energy efficiency of the T-series models is only found out under heavy multi-threaded computational workload. In idle states, with single-threaded operation, or when using the graphics core, the T-series processors do not give any serious advantages in terms of consumption.

All this means that there is practically no point in using special energy-efficient Sandy Bridge options for the sake of energy savings alone. Considering that in real life the maximum processor load is sporadic, T-series processors will not give a significant benefit when paying for electricity bills.

The real and indisputable advantages of these processors are manifested in something else - when, for some reason, it is necessary to limit the maximum consumption or heat dissipation from above. For example, if the system is assembled in a case that makes it possible to accommodate only a low-efficiency cooling system or in the case when a low-power power supply is forcedly used, Intel T-series processors can be really indispensable.

However, the limitations in power consumption and heat dissipation significantly affect the speed. From the point of view of peak computing performance, processors with a thermal package reduced to 45 and 35 W work on average 15-20% slower than conventional CPUs of the same class and similar cost. However, in the case of the Core i5-2500T and Core i5-2390T, such a significant lag is manifested only under heavy multi-threaded load, in other situations, these economical processors are seriously helped by the aggressively tuned Turbo Boost technology. Another pair of T-series processors, Core i3-2100T and Pentium G620T, does not have Turbo Boost support and lags far behind full-fledged counterparts in any scenario.

But it is not all that bad. The Core i5-2500T and Core i5-2390T are unique in terms of performance and are able to outperform conventional 95W and 65W processors in a number of ways. In particular, the Core i5-2500T has the fastest graphics modification. Intel cores HD Graphics 2000, which provides faster 3D performance with Quick Sync technology than most LGA1155 siblings. The Core i5-2390T can be called the fastest dual-core desktop processor based on the Sandy Bridge microarchitecture.

As a result, we come to the conclusion that the T series processors, and especially those that belong to the Core i5 family, are very curious products that sometimes have even completely unexpected advantages. However, in general, we can only talk about the Core i5-2500T, Core i5-2390T, Core i3-2100T and Pentium G620T as niche products that are really interesting only in a limited number of situations. At the same time, we should not forget that in many cases, instead of T-series processors, you can generally do with 65-watt Pentiums, which in reality often demonstrate comparable or even lower power consumption than 45- and 35-watt processors of the Core i5 and Core i3.

In other words, choosing the right CPU for an energy efficient system is a very difficult question, and there is no single recipe for the answer. The variant proposed by Intel with special modifications with low thermal packets should not be dismissed, of course, but we cannot say that it will be the only correct one in any case.

Other materials on this topic

Real Fusion. AMD Llano A8-3800 APU Review
Review of processors Pentium G850, Pentium G840 and Pentium G620
Review of processors Core i3-2120 and Core i3-2100

Introduction.
For a long time, I wanted to dwell on the issues of ensuring the reduction energy consumption modern personal computers and laptops. Many users justifiably ask the question: "Why is this necessary? - the manufacturer has already taken care of all the intricacies of the power consumption of my system. As experience shows, unfortunately, this is almost always not the case. If laptop manufacturers are still trying to somehow reduce the power consumption of their devices, then with personal computers, as a rule, everything is in a state of disrepair.

Power consumption of personal computers and must be reduced for the following reasons:
- by reducing the power consumption of your laptop, you extend its time autonomous work,
- by extending laptop battery life, you achieve lower charge / discharge cycles battery and extend its service life,
- along with energy consumption, the heat dissipation of laptop or personal computer components is also reduced, which allows, on the one hand, to increase the stability of the system, on the other hand, to extend the service life of electrical components,
- reducing the power consumption of a personal computer and laptop will reduce the cost of electricity. For many, this is still not critical, but the cost of electricity is growing day by day, government policy is forcing citizens to install electricity meters, the number of computers in the family is increasing from year to year, the duration of their work is lengthening proportionally, so each of them is interested in technologies to reduce energy consumption. US.

Determination of the key components of the energy consumption of the system.

Despite being modern Personal Computer and notebook so different from each other, as a rule, they are completely identical in structure schemes. In a laptop, manufacturers are trying to arrange everything in such a way as to minimize the total size as much as possible. While any personal computer is a modular system, any component of which can be replaced without any problems.

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The following figure shows the components standard system unit ... Knowing these components of the system will allow you, even at the stages of assembling or upgrading your computer, to determine those parameters that will allow you to reduce the power consumption of the system. So, a modern system unit contains:
- frame,
- power unit,
- motherboard,

RAM,
- video card / video cards,
- hard disk / drives,
- CD drive,
- floppy drives,
- card readers,
- cooling systems for the processor, case.
Sound cards, TV tuners in a separate version are rarely found in modern computers. Firstly, all existing motherboards have built-in sound controllers that are not inferior in sound quality to cheap sound cards and cards in the middle price range. Second, TV tuners are out of date, just like coaxial television. In the era of FulHD, IP-TV, DVB talks about TV tuners unnecessarily.

Energy saving: case and power supply.

For many, it may seem strange to discuss the power supply and frame in the context of energy saving technologies. Nevertheless, practice shows that users often choose a corpus by outward appearance and its price parameter. At the same time, it should be understood that a small-sized, poorly ventilated case will contribute to overheating of system components and reduce the stability of the same processor, RAM, motherboard with a decrease in supply voltages, which we will do in the future.

Power Supply can become a source of inefficient energy consumption in the first place. Any modern power supply must provide high efficiency when converting current high voltage at 12, 5 and 3.3 volts.

Any modern power supply unit complies with one of the series standards 80 Plus... The 80 Plus standard was adopted back in 2007, as part of the energy-saving Energy Star standards of the fourth revision. This standard requires power supply manufacturers to provide 80% efficiency of their devices under various loads - 20%, 50% and 100% of the rated power.

It follows from this that in order to maximize the efficiency of your PSU, it must be loaded at least 20% of its rated power. It is absolutely wrong when a user purchases power supplies with a "reserve" of 900 and 1200 watts. When choosing a power supply, be guided by the fact that without a load on the system, the load on it should not fall below 20% and it must have an 80 Plus certificate of conformity.

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In fairness, it should be noted that today the standard 80 Plus differentiated into the following categories:
- 80 Plus
- 80 Plus Bronze
- 80 Plus Silver
- 80 Plus Gold
- 80 Plus Platinum.

The difference between the standards lies in the provision of higher efficiencies within the 80 Plus family. While at 50% load an 80Pus PSU provides 80% efficiency, expensive 80 Plus Platinum PSUs provide 94% or higher efficiency.

Energy saving: motherboard.

Today, motherboards are developing as quickly as possible, keeping up with the development of processors. It should be understood that motherboards are made up of different sets of controllers, which is the main task of the motherboard to ensure that they work together. In most cases, the power consumption of the motherboard depends on the type of northbridge and southbridge used. Modern north bridges have significantly reduced their energy consumption, which has led to a reduction in the size of their cooling systems. Many users remember the time when the northbridge cooling system consisted of multiple heat pipes connected to cooling radiators. The appearance of the latest generation of system logic from Intel allowed us to move back to the level of conventional heatsinks again.

Due to general trends, many eminent motherboard manufacturers, such as Gigabyte, ASUS, MSI showcase their new "eco-friendly" products at exhibitions. As a rule, environmental friendliness of these solutions is achieved by optimizing the power supply circuits for the processor and video cards, which are the main consumers of any system unit. As a rule, this is done through the use of multiphase voltage regulators of processors.

Modern motherboards, are used in power supply circuits from six to twelve voltage stabilizers. These circuits significantly increase the stability of the supplied voltage, but increase power consumption. Therefore, manufacturers of "eco-friendly" motherboards equip them with technologies that, at low load on the power supply system, turn off part of the phases, and the processor is powered by one or two phases of voltage stabilizers.

When buying a motherboard, you should also be more careful. Acquisition of "fancy" motherboard always results in increased power consumption. If you never need a FireWire port, don't overpay for it and then pay monthly for the electricity its controller on the motherboard uses.

Power saving: processor.

Leading processor manufacturers AMD and Intel over the past decades have been working to reduce the energy consumption of their products. To its credit, the whole relay race was started by AMD, in which it held a solid leadership for two to three years. There was a time when AMD processors with Cool "n" Quiet technology had significantly lower power consumption than Intel processors of the Pentium 4 and Pentium D lines.

Intel quickly caught up with the technology EIST- Enhanced Intel SpeedStep Technology, which has proven itself in the latest generations of processors. While the new processors from Intel are acquiring more and more energy-saving technologies and increasing performance, we do not see any significant leaps forward from AMD.

As you know, the processor is the key energy consumer of any personal computer or laptop, so we will focus on the issues of reducing its energy consumption.

In order to understand how you can reduce energy consumption, you must clearly understand what it depends on. The power consumption of a modern processor depends on:
- from the supply voltage supplied to the transistors,
- processor frequency. The processor frequency is formed from the product of its multiplier by the bus frequency.

Basically, technology Cool "n" Quiet and EIST are engaged in reducing energy consumption precisely due to these two parameters. Unfortunately, most often we are faced with work not with the processor supply voltage, but with the work of its frequency. As the load on the processor decreases, energy-saving technologies lower the processor multiplier and thereby reduce the processor's power consumption. When a load appears on the processor, the multiplier returns to its previous values, and the processor works as if nothing had happened. Unfortunately, this method of reducing energy consumption does not always lead to high energy efficiency. Let's show it with an example.
As an example, a Core 2 Duo processor with a nominal operating frequency of 2.0 GHz is selected.

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The diagram shows that the temperature of the processor without turning on the power-saving mode, with a nominal multiplier of x12 and a supply voltage of 1.25 volts, we have an operating temperature of about 55-56 degrees in idle.

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After applying the load to the processor, under the same operating conditions, we fix the average operating temperature of the order of 71-72 degrees, which was recorded in our diagrams.
The core temperature is measured using internal sensors, so the errors are minimal. Considering the fact that there is a direct proportional relationship between the processor's power consumption and its operating temperature, we will focus on this parameter when assessing its energy efficiency.
At the next stage, we reduced the multiplier to the lowest possible value, to 6. At the same time, the processor frequency was 997 MHz, roughly it can be rounded up to 1 GHz. The supply voltage remained unchanged at around 1.25 volts.

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From the presented data it can be seen that in idle mode, the operating temperature of the processor changed very little, it remained, as before, within 55-56 degrees. Hence, the conclusion suggests itself that we gain very little from a simple decrease in the processor frequency.

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After that, we applied the load to, but left the multiplier and the operating voltage of the processor at the same level. Naturally, such testing is only of practical importance; we do not recommend implementing it in real life. This is due to the fact that its performance depends on the frequency of the processor, and no one buys a high-frequency processor for its subsequent operation at lower frequencies. After stabilizing the temperature values, we got an average operating temperature of 65-66 degrees, which is six degrees lower than when the processor was operating at the nominal frequency of 2 GHz.
From all this it follows that there really is energy saving from lowering the processor's operating frequency by changing the multiplier value, but it is not the level that we would like to see in each specific case. Therefore, we start working with processor voltage.

Our processor and motherboard allow you to change the processor voltage in the range of 0.95-1.25 volts. The step is 0.0125 volts. This is due to the fact that the processor is installed in a laptop, whose motherboards rarely allow changing the operating voltages of components in wide ranges.
In order to prove the effectiveness of reducing the operating voltage of the processor in terms of reducing its power consumption and heat dissipation, we will leave its operating frequency at 1 GHz, but in parallel we will reduce the operating voltage to the lowest possible values, - 0.95 volts.

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This manipulation allowed us to reduce the idle temperature of the processor to 45-46 degrees, which is shown in the diagram. In this mode, we achieve the lowest possible processor power consumption. Reducing the operating voltage to 0.95 volts allowed us to reduce the operating idle temperature by 10 degrees !!!

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To evaluate the effectiveness of the method for reducing the operating voltage of the processor, we applied a load to it. As a result, we got an operating temperature in the load equal to 50-51 degrees, while without changing the voltage and similar system performance at a frequency of 1 GHz, we previously received 65-66 degrees. The data we obtained are recorded in the diagrams.

Processor power consumption: conclusions

- From all of the above, it follows that to ensure high processor energy efficiency you should not only reduce the operating frequency of the processor, as is done by many laptops and personal computers in the framework of energy-saving technologies from Intel and AMD. Reducing the frequency of the processor should always be accompanied by a decrease in its operating voltage.

Considering the fact that any processor can operate at lower voltage at lower frequencies of its work, you should choose your minimum stable voltage for each frequency of its work.

To determine approximate workers stresses for each frequency (multiplier) of the processor, it is enough to plot a graph of the direct dependence of the minimum voltage on the frequency by plotting the maximum and minimum values. This will greatly facilitate the work of novice users.

- To ensure the required energy efficiency of the processor, it is necessary to properly tune existing technologies or use third-party software products that could reduce the frequency of the processor, its voltage at low load and increase them when it rises.

CPU Power Saving: RightMark CPU Clock Utility (RMClock)

The utility is lightweight, of the order of 250 kilobytes... No installation required, just unzip it to the folder of your choice and run the RMClock.exe file. For simplicity, a link to the archive with the program will be provided at the end of our article.

At the time of this writing, the latest program version 2.35 has the following functionality within the framework of free use:
- control of the clock frequency of processors,
- throttling control,
- control of the processor load level, processor cores,
- monitoring the operating voltage of the processor,
- temperature control of the processor / processor cores,
- continuous monitoring of the specified parameters,
- the ability to change the processor voltage from operating system,
- the ability to change the processor multiplier (its frequency) from the operating system,
- automatic control frequency and processor voltage depending on the supplied load. The concept is called "Performance on demand" or "performance on demand".

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After launching the software product, you will find yourself in one of the sections of its menu. We will list all the functionality of RightMark CPU Clock Utility in order. The About section contains information about the developers, their site, and a link to the license agreement. The basic version of the product is supplied free of charge for non-commercial purposes, no registration is required. There is a professional version, which provides a much wider functionality of the system settings and costs a symbolic $ 15. For a novice user, the capabilities of the basic version are quite enough.

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In the " Settings"the program settings are presented for the convenience of its use. Unfortunately, Russian language pack, which was found in previously released versions of the product, was not found in our case, but there is nothing to worry about. In this tab, you can select the color of the design and, please pay attention, - the autorun mode.

The subsection " Startup options". RightMark CPU Clock Utility autostart when the operating system is loaded makes it as easy as possible to solve energy saving issues without interfering with Computer BIOS, which is especially useful when the BIOS does not provide any options for changing the operating voltage and multiplier of the processor. The same is found in the BIOS "ah of modern laptops.

By ticking the box of the item " Start minimized to system tray"you save yourself the trouble of constantly closing the program window at the next start. It will perform its tasks after automatic start with preliminary clotting.

Paragraph " Run at Windows startup: "allows you to set the automatic launch of the software product and choose how to do it. In our case, we carry out automatic launch through the registry, there is also the possibility of automatic launch through the" Startup "folder. Both options work fine, from Windows XP to Windows 7.

It is possible to record the necessary parameters of the processor in Log file... This parameter is sometimes necessary to find out the reasons for the unstable operation of the system.

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In the " CPU info"provides information about the processor, its characteristics at the moment. Supported energy-saving technologies are listed. The more modern processor, the more technologies it supports.

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In the " Monitoring"diagrams of changes in the operating frequency of the processor core, its throttling, load on it, multiplier, operating voltage and temperature are presented. The number of tabs corresponds to the number of processor cores.

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In the " Management"the user is given the opportunity to choose a method for switching multipliers, methods for determining the actual load on the processor, integrating the software product with energy-saving technologies of the operating system.

Paragraph " P-states transitions method"allows you to select the method of transition from one given combination of multiplier-voltage to another. The following options are available:
- Single-step: the multiplier is switched in steps of one. That is, when moving from a factor of 10 to a factor of 12, there will always be an intermediate link 11.
- Multi-step: the transition will be performed with a variable step. In the case of our example, from 10 immediately to 12.

Paragraph " Multi-CPU load calculation"allows you to determine the method for determining the processor load. This parameter will affect the switching speed of the multiplier-voltage combination on the processor. that the assessment will be carried out according to the maximum load of any of the processor cores.

Paragraph " Standby / hibernate action"allows you to select the action of the program when it enters hibernation or sleep mode. As a rule, leaving the current work profile is sufficient.

In chapter " CPU Default Settings"the following items are presented:
- Restore CPU defaults on management turns off, which allows you to restore the original parameters of the processor after selecting the "No Power Managemet" mode.
- Restore CPU defaults on application exit, which allows you to restore the original processor parameters after turning off RightMark CPU Clock Utility.

In the "CPU defeaults selection" section, the method for determining the multiplier-voltage combinations for the processor is selected:
- CPU-defined default P-state, the combination is determined by the processor,
- P-state found at startup, combinations are determined when the program is loaded,
- Custom P-state, combinations are set manually.

Paragraph " Enable OS power management integration"allows you to create a profile in the system power diagrams called" RMClock Power Management ".

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In chapter " Profiles"the user is prompted to set the very same multiplier-voltage combinations, - P-state. First, it is suggested to select profiles depending on the power consumption mode, - network or battery / UPS.

Below it is suggested to choose processor multipliers and the tension for them in each case. Typically, I choose three values:
- minimum multiplier and minimum voltage for it,
- maximum multiplier and minimum operating voltage for it,
- the average value of the multiplier, and the voltage for it is set by the program itself based on the maximum and minimum values.

Typically, this approach is suitable for most laptops and personal computers. Naturally, there are exceptions, and the user has to select the minimum voltage for each multiplier for a long time.

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Then check the boxes for already selected profiles in the corresponding versions of the program:
- No management - no management, no settings needed
- the tabs "Power Saving", "Maximal performance", "Performance on Demand" are essentially equivalent and allow you to set the ranges for changing the processor voltage multipliers.

For example, in our case, for the tab " Power saving"we have chosen the lowest possible multiplier and voltage, for the" Maximal performance "tab, the maximum multiplier and minimum operating voltage at a given frequency for the processor.

See performance on demand " Perfomance on Demand"we chose three multiplier-voltage combinations:
- x4-0.95 volts
- x9-1.1 volts
- x12-1.25 volts.

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Then hover over the icon in the notification area of ​​the desktop of the program RightMark CPU Clock Utility and select the necessary processor parameters that should always be shown to you and select the current work profile. I always monitor the frequency of the processor and its operating temperature, which is always convenient and somewhat interesting.

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The figure shows three pictograms in the desktop notification area:
- icons for RightMark CPU Clock Utility,
- current processor frequency,
- its current temperature.

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The screen shows diagrams of the processor's operation in the " Performance on demand". It can be seen how the software product, with an increase in the load on the processor, stepwise increases its multiplier and voltage, first up to x9-1.1 volts and, if necessary, up to the maximum x12-1.25 volts. As soon as the load drops, everything is returned stepwise.
This adjustment has little or no effect on the overall performance of the system.

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In the " Battery info"it is proposed to select the methods of notification about the state of the laptop battery.

In the " Advanced CPU settings"it is suggested to select the processor temperature sensors to be polled, the power saving technologies to be enabled.
All these energy saving technologies are described on the website Intel... We just want to say that, as a rule, turning them on does not affect the stability of the system, so why not turn them on?

Our processor belongs to the early processor family Core 2 duo... Modern processors support technologies that are not active in our country:
- Engage Intel Dynamic Acceleration (IDA)
- Enable Dynamic FSB Frequency Switching (DFFS)

The first technology Allows the processor to increase the multiplier of one of the cores while not loading the other. For example, two processor cores operate at a frequency of 2.2 GHz. The processor estimates that the load is applied to only one core, then its multiplier will be increased, and it will start operating at 2.4 GHz. The technology is interesting, but dangerous on overclocked processors.

Second technology allows you to achieve an even greater reduction in the operating frequency of the processor in idle modes. Earlier we said that the final processor frequency is always the product of a multiplier by the system bus frequency. Modern Intel processors using DFFS technology allow decreasing not only the multiplier value, but also the bus frequency, which allows reaching even lower frequencies. This technology it is also dangerous for overclocked processors, as you can get instability from the RAM side.

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Perhaps this is all that we wanted to tell you about the software product. RightMark CPU Clock Utility... It remains to advise to follow her updates. At the same time, it makes no sense to update when everything has been working stably for many months. It makes sense to look new version when changing the processor or moving to a more modern operating system.
Using the program RightMark CPU Clock Utility will allow you to maximize the life of not only your processor, but also the motherboard's power supply system, as well as significantly reduce the noise from the processor cooling system, which will not strain to cool it when you print, watch movies or just flip pages on the Internet.

Processor power consumption: determine the minimum operating voltage

In my article, I have repeatedly pointed out that it is important to determine the minimum operating voltage for each processor frequency. This is done through trial and error. Typically, the following cycle of tasks is executed sequentially:
- voltage reduction by one point,
- checking the stability of the processor in a stress test software product,
- decrease or increase in voltage by one point, depending on the results of stress testing.

There are many software products available for stress testing processors. They were described in one of our articles. I think the most valuable of these is the Prime95 program. A link to it will be provided at the end of the article. It is completely free and available for download on the web.

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Its last version was released in 2008, just when it was necessary to introduce multicore in testing. It is possible to select different testing methods, indicate the duration of testing, the frequency of testing, etc.

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Choose a testing method in the " Options"=> "Torture test"and run it. The duration of testing is completely up to you. As a rule, when determining the approximate minimum voltage, I wait either for the first error, or I test for half an hour. If half an hour of the test passed without errors, we lower the voltage by one point and go again.
After you have decided on the minimum tension finally, it makes sense to leave the test overnight. For several hours of painstaking work, it is almost always possible to identify the errors that arise.
Often, the operating system freezes or, at best, issues " blue screen of death". This indicates that the voltage is too low and an error has occurred - you should raise the operating voltage on the processor for a given frequency.

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In our case, we have determined the minimum operating voltage for our processor... As it turned out, at maximum frequency at 2 GHz, our processor does not need 1.25 volts at all. It works quite stably at 1.00 volts. Operating system stability was also detected at 0.975 volts, but Prime95 reported an error that disappeared after raising the voltage to 1.00 volts.

As a result, we have

:
- a processor with a constant performance level and a frequency of 2 GHz,
- the maximum operating temperature at load is 62-63 degrees, instead of the usual 72 degrees,
- lower power consumption, which allows without any power consumption schemes from Acer, Asus, Samsung, Gigabyte to maximize the duration of the laptop battery life without losing the performance level,
- Lower power consumption will reduce electricity costs, especially if you specify these values ​​in the RightMark CPU Clock Utility software product described above.

In fact, such a low operating voltage for an overclocker processor always speaks of one thing - its high overclocking potential. But other articles will be devoted to the nuances of overclocking - the topic of overclocking a processor goes beyond the topic of energy saving. Conclusion.
After reading the article, the user should have a question: "Are manufacturers really so inept that they themselves do not lower the operating voltage of processors, especially in laptops, where it is so critical?" The answer is simple and lies in the fact that processors are produced in large quantities, laptops also come off the assembly line. It is not in the interests of manufacturers to delay the production process, so someone is lucky and his processor shows miracles of overclocking, while someone refuses to do this, someone's processor works at a voltage of 1.175 volts, and for someone it is stable even at 0 , 98 volts. Buying electronics is always a lottery. What is hidden under the label in each case is only learned in practice.
In conclusion, I would like to thank the software developers RightMark CPU Clock Utility and Prime95 to whom our portal MegaObzor presents a gold medal of honor. We are waiting for your questions and remind you that everything that you do with your electronics, you do at your own peril and risk.

RightMark CPU Clock Utility can be found at.
The program described in the article Prime95 can be found at.

The processor is usually the most power hungry component inside the average desktop PC. Processor power consumption first became a major concern when Intel began to approach the 4 GHz threshold with the Pentium 4 processor. consuming more than 100 W of energy, for which a powerful cooling system became necessary. However, power consumption and performance didn't go well with this chip. The appearance of the first dual-core Pentium D 800 processor made the situation even more complicated, and this was the case until the Core 2 Duo was released about a year and a half ago. Since then, we've seen nearly 400% gains in performance per watt, from the Pentium 4 600 line to modern Core 2 processors. We'll take a look at some of the evolutionary features in this article.

When we estimated the typical power consumption of two systems AMD and Intel, then we tracked the energy required to perform real tasks over a period of time, which we simulated using BAPCo's SYSmark 2007. This test is based on real applications that process data in a multitasking environment. power consumption of the system and components, these numbers provide only a fraction of the information.Power consumption should always be correlated with performance, since a faster system can transition to an energy efficient state faster than a slower system, resulting in large energy savings over a long period of time, even if even in instantaneous values, a faster system is more energy efficient.

V our article we evaluated the AMD Athlon 64 X2 5000+ (65nm) and Intel Core 2 Duo E6400 processors. Both processors are fast and efficient dual-core processors, but the Intel Core 2 Duo was able to win the battle for efficiency thanks to its performance advantage - the processor went into an idle economy faster than its AMD counterpart. But what if you compare a Core 2 Duo with a Core 2 Quad processor? And how much more efficient is this processor than Pentium 4 and Pentium D? Let's see!

3.0 GHz processors

Although Intel changes Socket 775 specifications with each new processor generation, the socket retains compatibility with older Socket 775 models. Suppose you need a new motherboard for Core 2 Duo (especially for the upcoming 45nm Penryn generation, which will be released in Q1 2008). it is quite possible to run even an old Pentium 4 on many modern Socket 775 motherboards. Thanks to such fortunate circumstances, we were able to test four different types processors on the reference test system.

We decided to choose the same operating frequency, which could be set for all processors in the line. We wanted to set the frequency from 2.6 to 2.8 GHz, but this turned out to be impossible due to the different frequencies of the CPU bus (FSB). Therefore, we had to stop at 3.0 GHz, which can be obtained on both Core 2 processors with FSB1333 and Pentium processors with FSB800. In the case of Core 2 systems, the memory worked at a frequency of 533 MHz (DDR3-1066 with latencies CL7-7-7-20), and with Pentium processors, DDR3 memory at 400 MHz was used (DDR3-800 and CL6-6-6-18) ... Actually, these are the default settings of the Asus P5E3 X38 motherboard. More high frequencies memory would lead to an increase in power consumption, albeit a small one considering the total power consumption of the system from 77 to 203 watts.

We were able to install the processors and run them at 3.0 GHz without any problems. We used maternal Asus board P5E3 Deluxe with BIOS version 0402 dated September 19, 2007.

CONTENT

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