It might, but then again it might not. Best case your BIOS detects it just fine or it reports back that it's an unidentified Phenom II X4. Worst case it doesn't POST. If your motherboard supports C3 CPUs then I say just go with a cheaper 955 instead and overclock it. The 955, 965, and 975 are essentially the same CPU just with different default multipliers.
Actually, the supported cpu list shows the 965 C3 revision as the fastest and latest AM3 cpu supported.
my system is
DFI UT 790FX-M2R
4GB OCZ PC6400 Reaper DC KIT cas 4 4-3-15 timings@ 800Mhz
TT Toughpower 1000W PSU
Phenoim II 940 @3.6 and 2000HT-2ghz NB@1.40v
Auzentech X-fi Prelude
2 Sapphire HD6970 CrossfireX.
Basicly since I don't have the budget to upgrade right now I was thinking it might be worth the 300$ or so to upgrade my 4GB OCZ Ram, and get a 965/(or 975 if it will work) and OC the 965 to 4.0Ghz or 4.2Ghz (if possible)Using Zalman CNPS9900(not the best but decent cooler. 3.6Ghz seems to be the max for the 940 CPU without excess Votage bumps and cooling.
since im a little CPU limited and 4GB is getting to low to have these days it seems like the best option for now to hold me off untill the next generation of components come out.
Swapping out your CPU to get to 4.0Ghz is only an 11% increase in clock speed. It's really not going to be too much of a difference. Faster RAM should help a bit though and with 8GB you can use high textures in Crysis2 (I tried it, you need more than 4GB with everything else on high)