No noticeable difference between DDR2 and DDR3. I have a 940, 965C3, 1055t, 4gb DDR2, 4gb DDR3, giga 790x and 890gx. I've ran everest on both the DDR2 and DDR3 system and the differences are minimal although this could vary depending on the type of memory,ram latency, and speed.
AMD likes...