Core Revision F: the Basics
AMD designed an updated core with K8 micro-architecture for their Socket AM2 platform. This core received the name of Revision F. So, all dual-core and single-core AMD processors with the integrated memory controller supporting DDR2 SDRAM will so far be based only on this core revision.
The major innovation introduced by AMD is certainly the DDR2 memory support. AMD simply replaced the integrated memory controller with a new one, since Athlon 64 micro-architecture allows making changes like that easily. At the same time, the new memory controller of the Athlon 64 processor family is not backward compatible with the regular DDR SDRAM. It means that from now on DDR memory can be regarded as an outdated solution. These days the two leading processor developers, AMD and Intel are quite unanimous in terms of the memory support: their platforms require DDR2 SDRAM. Of course, this should affect the DDR2 prices, so that we would expect the DDR2 SDRAM prices to drop below the DDR prices for the modules of the same capacity fairly soon.
Returning to the DDR2 SDRAM support by the core Revision F memory controller I have to stress that it officially supports DDR2 with up to 800MHz frequency. In other words, AMD managed to introduce DDR2-800 SDRAM support in its platforms ahead of Intel. Of course, the new AMD CPUs are also compatible with the slower DDR2 memory working at 667MHz and 533MHz frequencies. However, since K8 micro-architecture will benefit much more from the low memory latencies, you need DDR2-800 to ensure that you get the highest performance gain possible.
Note that the memory controller of the new core has traditionally acquired a slightly longer list of supported DDR2 frequency dividers than the official specification claims. As a result, some mainboards will even allow using Socket AM2 Athlon 64 processors with DDR2-1067 SDRAM without clock frequency generator overclocking. However AMD doesn’t officially claim support of DDR2 memory faster than DDR2-800 yet.
Besides the DDR2 SDRAM support, core Revision F can boast a few additional features. For example, Athlon 64 processors for Socket AM2 support Pacifica virtualization technology. This is AMD’s response to Intel’s VT that has been first introduced in Presler based CPUs.
Another important achievement resulting from the transition to AMD’s new Revision F core is the lowering of processors’ power consumption. Although AMD continues manufacturing the CPUs with the 90nm technology (using SOI and DSL technologies), Socket AM2 solutions boast lower heat dissipation and power consumption than their Socket 939 counterparts. By moving the Athlon 64 X2 processor family to the new core AMD has formally lowered the maximum heat dissipation by 19% (from 110W to 89W). As for the single-core Athlon 64 processors, the Revision F core allowed to reduce their maximum heat dissipation by 30%: from 89W to 62W.