Socket AM2+ / AM3
Phenom II X2 565 Game Requirement AnalysisThe Phenom II triples the shared L3 cache size from 2MB (in the original Phenom line) to 6MB, leading to benchmark performance gains as high as 30%. In another change from the original Phenom, Cool 'n Quiet applies to the processor as a whole, rather than on a per-core basis. AMD implemented this in order to address the mishandling of threads by Windows Vista, which can cause single-threaded applications to run on a core that idles at half its clock rate.
Socket AM2+ versions of the Phenom II (920, 940) lack forward-compatibility with Socket AM3. Socket AM3 versions of the Phenom II are backwards-compatible with Socket AM2+, though this is contingent on motherboard manufacturers supplying BIOS updates.
Source[ Wikipedia ]