I'm going to run the Core 2 Duo E6600 for a little while yet, waiting for the i7 Quad to drop in price, I'll also need a new motherboard for the i7 as is. The cpu is overclocked, runs at 3GHz. My bottlneck is gpu and RAM right now. I can't afford a new cpu, gpu, monitor, RAM and motherboard at this time. With a new gpu I'll also need a bigger power supply I'm guessing and hardware isn't exactly cheap here in Norway...
I'll probably do the full work-up in the spring and throw in a Quad cpu, replace the motherboard and possibly upgrade to some faster RAM eventually!
My new monitor will run at 1920x1080, its the new Samsung P2770FH!







