I have a first generation intel iMac - 20" 2.0 GHz Core Duo with a Radeon x1600 (256 megs of VRAM). I did some searching on the forums but most of the threads on overclocking really didn't have a ton of useful information... they consisted mostly of speculation. I'm interested in overclocking in Windows XP, NOT OS X. I just downloaded ATITool 0.26. and it named my default profile (89.95/89.95). I don't think that's significant but I figured I'd mention it anyway. It also lists the default values for my core as 1326.76 and my memory as 1319.27. Unfortunately, it doesn't tell me what those values are. I doubt that they're MHz because that seems pretty high and we all know my x1600 isn't running at that speed. I'm not interested in enormously increasing the clock speed. I was thinking more along the lines of mild overclocking that'll give me maybe a 5-10 fps boost with low-medium settings in a game like Mass Effect. While heat is certainly a concern, this is a 20" iMac case, not a macbook pro case. Does anybody have any recommendations, like how to actually find out my current clock speeds?