I am assuming the i7-920? That is still an awesome cpu and overclocks like a boss. What cooler do you have? And read this guide: http://www.overclock.net/t/538439/guide-to-overclocking-the-core-i7-920-or-930-to-4-0ghz
Your cpu can handle up to the gtx680 with some mild overclocking.
thanks a lot man, and yes it is the i7-920
I'm surprised this cpu is still holding up to even handle the gtx680 with mild overclocking, good news
EDIT: i have arctic cooler series 7 rev 2 heat sink + fan