I just recently got an msi geforce 6600gt and isntalled a zalman 700 fan and arctic silver which reduced it from about 55-60 idle and 75-80 load to 40-45 idle and 50-55 load. Before I could only overclock to about 540 core and 1130 mem but with the new fan and a.s. I'm sitting at 570/1175. The one thing I'm a little confused about is that my 6600gt doesnt seem to want to go over that 570 core mark or it becomes unstable but I've seen ton of people easily go above 600. I can get my core to about 575 or 580 at most but I have to drop my mem down a TON and it doesn't seem to work out in my favor in the benchmarks. Right now I'm pretty sure oc'ing right is getting a good mix w/o having the sacrifice core or mem alot but I just wanted to hear what the pros have to say.