| posts: 29,443 | Location: Hampshire, UK
I fail to see why most would say go for a new rig, quite the opposite, most will say to stick. that i7 920 has plenty of juice for any game out there.
OP, if I was you, I'd get a decent 3rd party cooler, something like a CM HYPER 212 EVO or similar, they can be had for around $35 and overclock that cpu to 4ghz or so. then upgrade your gpu to something like a gtx 760/hd 7950 or better, depending on your budget. if you have enough left, get a SSD, even if a small 64gb one, it'll be enough for your OS and all the essential apps.