so are you just overclocking to kill time before ivy drops or are you just tweaking for fun?
any software is gonna be off a little bit... but since you can't really stress test while in BIOS it's basically the only reliable way. when i had my Q6600 OC to 3.2Ghz my temps were around the same on air and dropped some on liquid. there will be a point where you can't keep it stable anyways but 4Ghz is possible, even though i wouldn't attempt it on air regardless. prime95 and other stress tests are fine, but i don't really consider them to be "real" conditions, meaning they aren't games or rendering or anything. just use real computing conditions to test stability... i don't even use that type of stuff any more i just attempt to use the computer normally and backtrack if something goes wrong
will be upgrading my 1st gen i7 as soon as i feel up to spending the money on some new gear... and i can promise that i will be overclocking the SHIT out of it hoping to get as close to 5Ghz on the same liquid loop. i'm hoping ASUS has some beastly mobos lined up because I want another express chipset like on my old rampage.