Does anybody here know whether efficiency of the Socket AM3 CPUs is affected by running them in an older Socket AM2 board, such as my MSI K9AG Neo2-Digital?
I'm currently using an Athlon X2 BE-2350 (AM2) undervolted to 0.875V @1.0GHz, 1.075V @2.1GHz. This runs at just the right temperature with a Scythe Ninja being cooled by just the exhaust fan at 600RPM. When running at stock voltages there is too much heat and the fan needs to ramp up.
There are times when I just wish for a bit more speed, but I would be willing to sacrifice the speed if it means staying with the low temperatures (and hence noise). The new AM3 Athlon X2 such as the 240 and 250 look perfect on paper, but all reviews tested them in brand new AM3 boards, not an older board.
I think the main important thing to consider is how much electricity the particular motherboard chipsets use. I doubt there's a big efficiency difference relating to the processor, DDR3 used less voltage then DDR2 but it's a very very small difference. Off the top of my head I happen to know some of the lowest power boards are
1 anything by via
2 AMD 740G/760G
3 Nvidia 8200