Overview of AMD L3 cache

[Botan]

While the large entry-and mid-Round-up still in the works, and take a few days more is claimed, we want to advance couple out a small portion of the article, which would in the mass of information in the final product does not always get the attention it deserves. This involves the question of who purchase an AMD processor, but should rather resort to a variant of L3 cache and for whom even the more positive spin without the additional cache server is sufficient. AMD currently makes it very skillfully in order to present with as little effort maximum models. Virtually all processors this year based on three different manufacturing masks. As would be first, the complete series of the flagship Phenom X4 900, but also the variations with the model numbers 800, 700 and 500 Propus. From this, the new Athlon X4 and X3 are carved, as the name implies Phenom II since its introduction always the existence of an L3 cache. AMD had at the beginning of 2009 delivered at the Phenom X4 is a small distinction. The talk is of the Phenom X4 800, one has reduced from six to four MB L3 cache. The effects of castration, we have light again for completeness also included in the overview. Really complete the overview is not so sure. It lacks the likely expected with four processors or three nuclei, which are also completely without L3 cache on the market. This Athlon X4 Phenom X3 600 and 400 are considered in due course in this test environment, and thus complete the story. In the test system, there are no surprises. It is completely to the processors used for system , the benchmarks and tests are identical. The coupling of these benchmarks is used as input, announced that only the consideration of the impact of L3 cache. But we caught a Phenom X2 545 and an Athlon X2 250, both clocked at 3.0GHz.

[softte]

Let's start but with the cache and memory tests of SiSoft Sandra, the output for each built-in processor cache a result. While lying in the L1 cache, the numbers are nearly equal to, offers the lower L2 cache of the Athlon X2 already a slightly higher data throughput. At the end, of course, add the L3 cache, but what does the theoretical data throughput, in practice, it is the benchmark, however no information. What strikes in the final rating of the dual-core processors at about four percent of beech comes mostly from the gaming sector, how to identify the individual ratings as well. The theoretical segment suggests in this rating as is known to not work because the result would otherwise end indeed almost in a stalemate. But what are the biggest differences, and where the lack of L3 cache will not notice? Not be noticeable, the lack of L3 cache when converting music, even when you convert videos are no significant differences. While packing with WinRAR wins the Phenom few seconds that it has to give in POV-ray and quasi TrueCrypt again. In the office sector, the battle between Athlon and Phenom II is balanced with two cores so close. At the games, however, very marked differences are noted, but almost only when these details and without looking at the same time in low resolution.

[Taipai]

L3 cache - We certainly welcome. But wait! Because if you throw the price with in the bowl and draws the energy needs of processors added both under load and in idle, it is more difficult with the election and suddenly moves depending on the application of the L3 cache-less Athlon past the Athlon X2 . The price difference between an identically clocked Athlon X2 and Phenom X2 is "only" about ten euros in the entry level but sometimes these are worlds and prompt 15 percent. In addition besides the saving in direct purchase is also the lower energy requirements of the Core II processors. It turns out once again that L3 cache brings not only performance but also requires a lot of power. For what is almost level in idle still is under load quickly apparent. Because there used the Athlon X2 in our complete system 16 percent more energy. What is left at the end to hold, then? Those who work primarily (and less) plays, can honestly take up Athlon II processor, as in the office will support the L3 cache, almost not at all interested, and the deviations are almost in the range of normal fluctuations. In addition, the buyer is then the lower power consumption and also slightly lower price when buying the best. If, however, meant primarily to the games, it should look rather wander the Phenom X2. The differences are depending on the game, resolution and detail level of 1 to 34 percent, which is a pretty impressive range. There was a gain over the Athlon X2, but it can be reported in every case.

[Shutdown]

For AMD, this development is both a curse than a blessing. The Athlon is produced with its much smaller manufacturing mask much cheaper, so the profit margin would be significantly higher for this processor. In contrast, however, the Phenom is II, two cores disabled, but in the more expensive production L3 cache. If the failure rate on nuclei in the Deneb processors are very high, the "leftovers" a blessing. This turns a semi-defective product, which would be used to simply wandered into the garbage, another processor, allowing the company to earn a few dollars. However, the production is already optimized so far and improved show that in manufacturing, very few defective quad-core processors, AMD has cut the processors themselves. Then, from the original blessing quickly a curse.

[Solaris]

Now that we have recently determined the impact of the L3 cache to the new dual-core processors, we focus today on the triple-and quad-core models. Especially with the quad-core models, this analysis is interesting because in addition to a completely bare processor without L3 cache, it is also the option of a slightly smaller cache. The third and most likely be after the Deneb is the most important since a few days, officially presented mask. Finally, for this will not only four-core processors are drawn, the three Kerner "Rana" and low-power versions with a TDP of 45 watts can be expected. What makes the Propus (and already at the Regor manufacturing mask) is that chip area and number of transistors is significantly lower due to complete lack of L3 cache and the effective yield of a wafer is much higher than the Phenom II This is in addition to the customers (lower prices and lower power consumption) but also the ongoing costs of AMD to the best. The big news of recent days was the "Propus" core, AMD Athlon without L3 cache - marketed as the Phenom II Behind this lies a new code name, the, without reliance on the L3 cache. AMD, it is possible for some time very skillfully and efficiently, with as "little" a maximum effort to present models can be. Virtually all desktop processors this year based on only three different manufacturing masks. First and foremost is the "Deneb" mask, which is identical to that of the 'Shanghai' server processors. From this quad-core mask there is currently the most branch in the trade.

[TechPredator]

Not be noticeable, the lack of L3 cache when converting music, even when you convert videos are no significant differences. While packing the Phenom wins with WinRAR II a few seconds here and there, one or more. In the office sector, the battle between Athlon and Phenom II with two, three or even four cores is ultimately close to balance, slight advantages in the form of a second win in certain applications but can already be seen for the Athlon. It reveal themselves in the quad-core processors in the blue bar at the performance differences of up to 38 percent (at the minima and maxima even more so) in games at low resolutions and with little detail. Since this value is not an isolated case (see blurb) and confirm the processors in the same series and also with two or three cores and with higher or lower clock this result is not only once, we have thus appears that the Achilles heel found the Athlon-II processors.

[Rover]

Since this value is not an isolated case (see blurb) and confirm the processors in the same series and also with two or three cores and with higher or lower clock this result is not only once, we have thus appears that the Achilles heel found the Athlon-II processors.

However, the resolution is screwed to a normal level of 1,280 x 1,024 pixels and also resorted to quality-enhancing drugs, is the limitation of the graphics card slowly. Nevertheless, differences are still visible up to ten percent. When the power consumption can be determined only a limited result, as AMD quasi provides each processor with a different voltage. So it happens that an Athlon X4 is 620 without L3 cache at 1.375 volts at the start, while the Phenom X4 810 requires only 1.30 volts. This alone ensures that the Athlon back is not only in the performance behind the Phenom, even in the field of power he has left behind. Especially in games, the cache server makes a positive impact, with the quad-core processors even more than in the first tested processors with two cores. And in practice, does the fast memory, integrated in one of the new AMD CPUs, no such great cost. It follows, therefore, at the end of an interesting constellation.

[T0tal L0$$]

A processor with four cores is at the same clock as fast as a processor with three cores, but can rely on the L3 cache. As these two examples in the form of our Athlon X4 Phenom X3 710 620 and also priced at the same level, the customer remains even now spoiled for choice. For AMD CPU is likely to be favored with such a decision of the Athlon, with the leaves eventually earn more. Because the Phenom comes in any design known from the more expensive the Deneb and are being scaled down accordingly for the different market segments. The Phenom X4 is based on the other hand (usually) on the Propus core, which is finished with a much lower surface and a significantly reduced number of transistors and correspondingly cheaper. If the charge is within the scope, you should grab at AMD actually always use a processor with the speed L3 cache.