I currently have an EVGA 680i Mobo (Part# 122-ck-nf68-t1) with a C2D E6400 and a 2X2gb set of corsair Dominator RAM (DDR2 1066 / PC8500). What quad core CPU's should I be looking at? I am running Vista Ultimate 64 bit and my 6400 is at 3.2 ghz. My cooler is a Tuniq Tower and Processor speed is not the greatest concern at the moment. I just want a Quad that will work well with my current system..........................