Best DDR3 SDRAM for AMD Phenom II X6
 

After our investigation of the effect that memory frequency and timings have on performance of different LGA1156 processors, the next step is to see how things are with other platforms. So our next subject is the Socket AM3 platform which has become increasingly popular after AMD’s launch of good and inexpensive six-core Phenom II X6 processors.

As you probably know, the memory controller of AMD’s modern 45nm processors, including the Phenom II X6 series, supports both modern DDR3 and outdated DDR2 SDRAM. This ensures compatibility with older Socket AM2+ computers but it is obvious that such processors are only going to show their best on new platforms. When we got Phenom II X4 processors compatible with both memory types, we performed comparative tests and found out that new mainboards with DDR3 memory instead of Socket AM2+ mainboards with DDR2 provided a performance boost of 5 to 10%. However, DDR3 modules were considerably more expensive, and the choice was not so easy. By today, prices of DDR2 and DDR3 have become similar (DDR3 is even occasionally cheaper), so there is no reason to consider the slower DDR2 SDRAM now.

http://www.xbitlabs.com/articles/mem...x6-memory.html