I'm dual-booting Win7 with Win8 on a second partition for testing. The one welcome feature that Win8 has over 7 is its support for SMT processors, which results in my cpu working as originally intended. Performance wise, I have seen a bit of an improvement in RoF, where frame rates are a little better and more stable. Task Manager indicates the first 4 cores loaded with the remaining 4 'parked', with enables boost state 'P0' (max. turbo) and results in lower temps due to half of the cpu being inactive.
A number of test sites have compared performance between the two and found no difference worth mentioning, the most recent one I've read was at
THG using IvyBridge. An
earlier test checking Bulldozer showed an increase over the 'patched' version of Win7, which is similar to my experience.
I intend doing a fresh install of Win8 when my SSD arrives, but will keep Win7 if only to fly CloD. The 'Metro' interface is pointless without a touch screen, and some apps don't work quite the same yet (the latest version of AfterBurner can't display VRAM usage in Win8 ), but it's not too different to 7.
I would suggest that only AMD FX users have any reason to change to Win8, unless of course you have a touch screen
