by Ilya Gavrichenkov
09/22/2010 | 04:11 PM
The recent IDF has given a lot of information to discuss Intel’s upcoming Sandy Bridge processor series. The promised enhancements in the microarchitecture are expected to push the performance bar of Core i3/i5/i7 processors to a whole new level while improving their energy efficiency. In other words, the Sandy Bridge family is a highly appealing offer, especially as it will be available in a wide price range. With this fact in mind, what might entice a user to prefer an alternative? Well, there is one substantial reason. The Sandy Bridge series does not sell yet. It is only going to be introduced in the first days of 2011 and won’t take part in the Christmas sales competition. So, if you are planning an upgrade or a purchase of a new computer before the next year, you have to choose from what CPUs are available now.
Considering this situation, the CPU makers have made some corrections to their price lists and issued new and faster modifications of their older products. For example, we have recently published a review of the new quad-core Intel Core i5-760 processor which is quite able to attract some user’s interest.
AMD is even more active than Intel in this respect. They are unlikely to offer a worthy alternative to the top-end and midrange models of the Sandy Bridge series when the latter comes out, so it is most important for the company to improve its market standing right now when the situation is not yet out of control. Today, AMD’s Phenom II and Athlon II series are not among the fastest, but do have a highly enticing price/performance ratio.
AMD carries out its aggressive market attack with all means available, the recent price cuts having been but the beginning. Now we witness the second phase during which AMD increases the clock rates of nearly all of its CPU series. The 45nm tech process used for Phenom II and Athlon II having matured, the clock rates can be lifted up without provoking a noticeable increase in power dissipation, so the new models can be quite competitive in their price categories. Besides, AMD attracts customers not only by offering products with good consumer properties but also by developing unique affordable processors like the six-core Phenom II X6 priced at below $300. Intel does not offer a direct opponent to such six-core CPUs, so AMD quite naturally extends this series further.
To be more specific, AMD announces as many as six new processors (and three more energy-efficient models are going to be distributed through OEMs) in different product series:
Thus, AMD’s desktop CPU families have the following structure now:
As you can see, AMD has tried to uniformly cover the entire price range from $50 to $300, offering as many different affordable CPUs as possible. This is reasonable since Intel’s CPUs do not have such a uniform coverage, leaving gaps both in the low and midrange price segments. AMD has always followed a highly flexible price policy, though.
We can also see that AMD has focused mostly on developing its Phenom II X4 series whose clock rates differ greatly from those of the other series. Well, Phenom II X4 processors do fill in the most popular market segment, so there is nothing surprising about that. And we guess that the clock rate of 3.5 GHz is not the limit and expect AMD to release a Phenom II X4 975 with a clock rate of 3.6 GHz later on.
In this review we are going to talk about the most exciting (and expensive) of the new products from AMD that hail from the Phenom II X6, Phenom II X4 and Phenom II X2 series. To remind you, the key distinguishing feature of Phenom II processors from their Athlon II counterparts is that they have 6 megabytes of shared L3 cache. Besides, they are more appealing for enthusiasts since most of them are Black Edition and have an unlocked frequency multiplier for easy overclocking experiments.
As a matter of fact, the newly announced CPUs are not particularly new. They are just clocked at higher frequencies thanks to the improved tech process. We are not talking new core steppings or redesigns here, so there is nothing unexpected about the new products’ specs.
The new Phenom II X6 1075T is an intermediary product in terms of frequency, fitting in between the earlier released Phenom II X6 1090T and 1055T. We have been expecting this model for a long time, actually, as this 3.0GHz processor was promised to us at the original announcement of AMD’s six-core series.
The quad-core Phenom II X4 970 is 100 MHz faster than the ex-flagship of its series, reaching a clock rate of 3.5 GHz. It has a somewhat mysterious background because we have been expecting AMD to offer a quad-core CPU based on the six-core Thuban die with two cores turned off. AMD had such plans at first but gave up the idea eventually. Unlocking disabled CPU cores in not a problem today and the sales of AMD’s expensive six-core CPUs might suffer if its quad-core CPUs were based on Thuban dies. Therefore, against our hope, the Phenom II X4 970 is a quad-core Deneb. This is AMD’s official position confirmed by the samples the company provided to hardware reviewers.
However, we have learned from unofficial sources that the Thuban-based Phenom II X4 970 will exist because it is not profitable for AMD to scrap all defective six-core CPUs. However, the company will try to do everything to prevent such CPUs from getting into ordinary users’ hands. It means they will be shipped through OEM channels and are not expected to sell freely. On the other hand, it is not often that AMD successfully differentiates its products in such a way, so we won’t be surprised to see the unlockable Phenom II X4 970 selling in retail in some regions. But not in mass quantities all over the world, of course.
It must be noted that increasing the frequency of the Deneb core to 3.5 GHz has not been easy for AMD. We infer this from the fact that our sample of Phenom II X4 970 is rated for a voltage of 1.4 volts, which is the top limit for Phenom II processors with a TDP of 125 watts. As a consequence, our Phenom II X4 970 is quite hot at work, resembling early C2-revision Phenom II X4 965 processors whose TDP was even lifted to 140 watts. AMD’s people told us that the company had managed to improve the thermal parameters of the new quad-core Phenom II X4 model at the last moment, though. Thanks to ongoing tech process improvements, the off-the-shelf samples will be colder and more overclockable than the prototypes. Unfortunately, we couldn't get a mature sample of Phenom II X4 970 before the announcement and cannot refute or confirm this fact.
The third new processor is a dual-core Phenom II X2 560 with a clock rate of 3.3 GHz. Besides its appealing $100 price and Black Edition marking, it is based on a full-featured quad-core Deneb die in which two cores are turned off by the manufacturer but can be with some luck enabled by the user.
Unfortunately, Turbo Core technology is only implemented in the six-core model out of the three new Phenom II processors. Thanks to it, the clock rate of the Phenom II X6 1075T can be dynamically increased from its default 3.0 GHz to 3.5 GHz when only three or fewer cores are in use. This technology being a unique feature of the Thuban die, it is easy to understand why it is not available on the Phenom II X4 970 and Phenom II X2 560.
As the new Phenom II series processors do not differ from their predecessors in anything but clock rate, we are not going to carry out a detailed comparison of their performance with Intel’s products. We just took four similarly priced LGA1156 processors: a quad-core Core i7-860 and a quad-core Core i5-760 (the former is more and the latter is less expensive than the Phenom II X6 1075T), a dual-core Core i5-650 (competes with the Phenom II X4 970) and a Core i3-540 (comparable to the Phenom II X2 560 in price).
Here is a full list of hardware components we used for our tests:
The Core i5-760, Core i5-650 and Core i3-530 do not support DDR-1600, so we used them with DDR3-1333 at timings of 9-9-9-27.
SYSmark 2007 shows the performance of a computer when executing typical scenarios in popular office and digital content creation applications.
Quite a lot of popular applications cannot make use of too many CPU cores, so multi-core CPUs prove to be not the best choice for them. For example, the new six-core Phenom II X6 1075T is slower than the quad-core Phenom II X4 970 in SYSmark 2007 despite its Turbo Cache technology which increases its clock rate under low to medium loads. It is also quite normal that the Phenom II X6 falls behind the quad-core Intel CPUs which feature a higher performance per core. On the other hand, we cannot say that the rest of the Phenom II processors, with fewer cores, perform successfully in SYSmark 2007. The quad-core Phenom II X4 970 is somewhat slower than the dual-core Core i5-650 whereas the dual-core Phenom II X2 560 is quite far behind the junior Core i3 series model. Thus, each Phenom II discussed in this review is inferior to its similarly priced opponent from Intel.
To show you the complete picture, here is a table with the SYSMark results sorted by application type.
As you know, it is the graphics subsystem that most often determines the overall performance of a computer in modern games if the CPU is fast enough (and the CPUs we are testing today are indeed fast). Therefore we run gaming tests in our CPU reviews without full-screen antialiasing and at low resolutions. So, the results are not indicative of how fast the particular game can run on modern computers but rather how well the tested CPUs can cope with gaming load. This can give us some insight into the future when graphics cards will get faster and the CPU may become the limiting factor.
Gaming is not a forte of AMD processors, either, but they perform better here than in the previous test. Modern 3D games cannot make full use of the six cores provided by the Phenom II X6 1075T, so the latter is not very fast. The Phenom II X2 560 is inferior to the dual-core processors from Intel which are endowed with Hyper-Threading technology which is quite useful here.
As opposed to its cousins, the Phenom II X4 970 is an excellent choice for a gaming platform since this quad-core CPU is positioned on the market as an opponent to Intel’s dual-core CPUs. Its four cores, clocked at a rather high frequency of 3.5 GHz, make it superior in games to the similarly priced Core i5 series offers. To put it in a different way: a quad-core CPU is the best choice for today's games. And since AMD offers cheaper quad-core CPUs than Intel, the Phenom II X4 series should be considered by gamers who are planning to build a new midrange gaming platform.
WinRAR cannot run in more than four execution threads when archiving data, so the overall picture resembles what we’ve just seen in the games. The Phenom II X6 is not as fast as we might expect and falls behind the quad-core products from Intel due to its rather low clock rate that neither the number of cores nor Turbo Core technology can make up for. The Phenom II X4, on the contrary, performs well enough. You should keep it in mind that this quad-core processor is competitive only because AMD positions it as an alternative to Intel’s dual-core models from the Core i5 and Core i3 series. The dual-core Phenom II X2 falls behind even the junior Core i3 series product, indicating that modern processors from AMD and Intel with the same number of cores deliver completely different performance.
Moreover, the dual-core Phenom II X2 560 is inferior to the Core i3-530 even in the TrueCrypt encryption system which is generally favorable towards the Stars (K10) architecture. On the other hand, the Phenom II X4 and Phenom II X6 perform well in the encryption tasks, being much faster than their opponents from the Intel Core i5 series. Here, the quad-core Phenom II X4 970 matches the speed of the more expensive Core i7-980 while the Phenom II X6 is far faster.
It is a known fact that AMD processors are inferior to Intel ones in Adobe Photoshop. The higher clock rates of the new Phenom II models do not change the situation: even the dual-core Core i5-650 is ahead of the six-core product from AMD when processing images!
We’ve got a similar picture when encoding audio in Apple iTunes but multi-core CPUs are useless here because this application can only utilize two CPU cores.
Video encoding and nonlinear video editing are popular tasks that call for advanced hardware resources. Here, the more physical or virtual (Hyper-Threading) cores a CPU has, the better it performs. And it is here that the six-core Phenom II X6 1075T can show its best, proving to be superior to every other CPU in terms of price/performance ratio. The quad-core Phenom II X4 970 looks good against its dual-core opponents, too. The Phenom II X2 560 is rather disappointing once again. In fact, AMD's dual-core products can only be interesting to customers in the entry-level market sector where Intel only offers its old LGA775 processors.
Final rendering can be done in multiple execution threads very efficiently. Therefore, this test produces the same picture as the video processing tests: the more cores a CPU has, the faster it performs. So, the six-core product from AMD is ahead of the quad-core solution from Intel and matches the quad-core and Hyper-Threading enabled Core i7-860. The quad-core CPU from AMD is expectedly as fast as the Core i5-760 and faster than the dual-core Core i5 and i3 series products. The dual-core Phenom II X2 is slow again because Intel’s dual-core solutions feature Hyper-Threading which helps them a lot in multithreaded applications.
Higher clock rates make CPUs consume more power. However, as the manufacturing process is being polished off, the thermal and electrical parameters of CPU dies improve. These two trends usually counterweigh each other, so newer CPUs working at higher clock rates do not differ much from their predecessors in terms of power consumption.
The graphs below show the full power draw of the computer (without the monitor) measured after the power supply. It is the total of the power consumption of all the system components. The PSU's efficiency is not taken into account. The CPUs are loaded by running the 64-bit LinX 0.6.3 utility. We enabled all the power-saving technologies for a correct measurement of the computer's power draw in idle mode: C1E, AMD Cool'n'Quiet and Enhanced Intel SpeedStep.
AMD processors are still less energy-efficient than their direct opponents from Intel. The Phenom II X4 970 is especially disappointing as its system consumed more power than the Core i7-860 based platform under load. AMD promises certain improvements for off-the-shelf samples of these new CPUs in terms of power consumption and heat dissipation. This can hardly change the picture dramatically, but the Phenom II X4 970 is likely to become more economical than the six-core Phenom II X6 1075T.
The new quad- and dual-core Phenom II processors do not differ much from the Core i5 and i3 series in terms of power consumption when idle. It means that modern power-saving technologies are so effective that the CPU is not the main consumer in an idle computer. Other components such as the graphics card, disk drives, mainboard and memory consume much more in this mode. Unfortunately, the Phenom II X6 1075T is not so economical when idle: although it has Cool’n’Quiet technology, it does not lower its voltage as low as its Deneb-core cousins do.
We know the overclocking potential of modern Phenom II processors well enough. Using air coolers, they can be clocked at frequencies up to 4 GHz. The new models can hardly change this much, but we can expect a certain increase in maximum frequency due to tech process improvements. So, we checked out the overclockability of each of the three new CPUs we had in our hands.
First we took up our Phenom II X6 1075T. This is an ordinary member of the six-core family and does not have an unlocked multiplier. Therefore, it can only be overclocked by increasing the base clock rate above 200 MHz.
We eventually made it stable at the expected frequency of 4.0 GHz. The base clock rate was set at 268 MHz and the CPU voltage was increased to 1.525 volts. As the screenshot shows, the overclocked CPU had a normal temperature: occasionally higher than 70°C according to the under-socket sensor during our stability check. It must be noted that we did not reduce the frequency multiplier of the CPU-integrated North Bridge, so the frequency of the memory controller and L3 cache grew up proportionally to the CPU frequency from the default 2.0 GHz to 2.68 GHz. Thus, the new Phenom II X6 1075T is no different from other six-core AMD processors in terms of overclocking potential.
Next we tried our Phenom II X4 970. It belongs to the Black Edition series and can be overclocked by changing its frequency multiplier.
Our Phenom II X4 970 was stable at clock rates up to 4.0 GHz (with air cooling). Thus, this new quad-core processor from the Phenom II series has the same overclocking potential as the rest of Deneb-core CPUs we have tested so far. The CPU-integrated North Bridge could be overclocked up to 2.6 GHz. To make the CPU stable we increased its voltage to 1.525 volts and the North Bridge voltage to 1.25 volts. When passing our stability tests, the CPU was as hot as 65°C according to the internal sensor which reported far more credible numbers than the under-socket one.
So, if off-the-shelf Phenom II X4 970s overclock better than the test sample, as AMD has promised to us, we can expect them to become highly valuable for Socket AM3 overclockers. This needs checking out in practice, of course.
Our third processor, the inexpensive Phenom II X2 560, is Black Edition, too. Besides that, it resembles the Phenom II X4 970 being based on the same Deneb die (with two cores turned off). That’s why our Phenom II X2 560 shows similar overclocking potential to its quad-core cousin.
However, we made our Phenom II X2 560 stable at 4.0 GHz using a lower voltage (1.5 volts). The CPU-integrated North Bridge worked at 2.6 GHz at a voltage of 1.225 volts. Interestingly, although we used almost the same voltages and frequencies as with the six-core and quad-core CPUs, the dual-core CPU had a much lower temperature.
However, it is not with sheer overclockability that the Phenom II X2 560 can excite an enthusiast. The more thrilling thing is that this dual-core CPU incorporates two disabled cores which you can try to turn back on. This is quite easy to do on most mainboards if the Deneb die this CPU is based on has no defects in the disabled cores: nearly every mainboard maker has implemented such a technology. By simply choosing an appropriate BIOS option or setting an onboard jumper, you can turn your Phenom II X2 560 into a quad-core Phenom II X4. This is not 100% guaranteed, but the mature 45nm tech process makes it far more probable. Our test sample transformed into a quad-core CPU without a single problem. Moreover, we overclocked it then to 3.9 GHz.
By the way, if your Phenom II X2 560 doesn’t work in quad-core mode for some reason, you can try to enable only one of the two disabled cores as modern mainboards offer this opportunity, too. So, a $100 Phenom II X2 560 can make a very valuable purchase because, with some luck, you can not only overclock by 20% but also double the number of its execution cores!
The Phenom II family is currently in dire straits really. The lack of a new competitive microarchitecture on AMD’s hands makes the Phenom II processors inferior to Intel’s modern products if you compare models with the same clock rate and number of cores. The only way for AMD to survive on the CPU market is to exploit the price factor and the company has been using it most flexibly by bringing new CPU models into those market niches which are not occupied by Intel's product range. We've got another illustration today: AMD has released new, somewhat faster modifications of its dual- and quad-core CPUs and extended its six-core series to attract more users with a carefully thought-out combination of consumer properties and price.
For example, AMD offers its six-core products in the price segment where Intel offers only quad-core ones. As a result, heavy multithreaded applications run very fast on the Phenom II X6 series. The new Phenom II X6 1075T extends the choice of inexpensive six-core CPUs, covering the price gap between the 1090T and 1055T. We guess this new in-between model will make AMD’s six-core processors more popular.
The quad-core Phenom II X4 970 looks most appealing in its price category, too. Why? Because it is pitted against Intel’s dual-core solutions and wins!
The dual-core Phenom II X2 560 didn’t look well in our performance tests against its Intel opponents. However, it is appealing for another reason. There is high probability of transforming this cheap dual-core CPU into a full-featured quad-core CPU with quite high performance. If viewed from this standpoint, the Phenom II X2 560 may be appreciated by thrifty enthusiasts.