Here's the deal. I've had my ASUS M4N72-E mainboard for 3 years now and it's still in good working order. I've been running a GTX460 SLI configuration on it for the last year or so.
When one of my EVGA GTX460s broke down I sent it RMA and after 3 months or problems (mine & EVGA's fault) it was replaced with a GTX660 earlier this week. Since I took the GTX460 from my son's PC to keep SLI running, I dropped the GTX660 in his. There the card is running perfectly.
Today I tested the card in my system to compare performance with the GTX460 SLI configuration. Oddly enough, the moment I dropped the GTX660 in my system, my system kept crashing and hanging itself up. I've updated drivers, removed AVG as virus scanner and cleaned up my registry with PC Tools. Nothing weird found, but still the problem of the GTX660 crashing and hanging up my system remained.
Now I'm back with my GTX460 SLI configuration and it looks like all is stable again...
AMD Phenom X6 1090T BE @3
8Gb memory 800Mhz DDR2 - 2x2Gb Corssair and 2x2Gb ICIDU
Creative X-Fi Fatal1ty Champion
Windows 7 x64 Ultimate
Anyone has an idea what the problem might be with the GTX660 in the above configuration? I really would like to run it in my system because of the much better performance with DX10/DX11 games ;-)
AsRock 990FX Extreme3
AMD Phenom II 1090T ~3.2Ghz
GEiL 16Gb DDR3 1600Mhz
ASUS GTX970 3x HD monitor 1920x1080