Aussie I'll get back to you in a bit, with the settings I'm currently using for 4.2ghz.

Good call from Leeghoofd, as well. Personally I use 1.3v for CPU FSB.

You also might want to check out the 790i Black Pearl thread over on the EVGA forum/790i. Mr Natural has posted a link for the XFX P05 bios, and it gives better memory stability than the EVGA one.

RLM