Well, after much more testing, benching, burn-in, etc last night and this morning - I've got to a conclusion. 300x9 is desktop stable, but not much more. No matter how I tune my ram from there (and a 8hr pass in Memtest came up clean) it's still not Prime stable. 285x9 on the other hand lets me tune my ram just like it's advertised at 2-2-2-8 @ 3.2v plus I can also ramp up the divider to 5:6 166 meaning the ram itself is running at 233mhz Prime stable. For the loss of 140mhz I'm willing to take it. I'll leave it at the current 2.56Ghz for the time being and benchmark the snot out of it - then if/when it'll decide it wants to try for 300 stable - I'll be back with updates Long story short, I think I've about monopolized enough time of the people in these forums - and hope that at least a few people can learn from my trial and error, day by day, blow by blow account of my A64 OC'ing attempts - from this thread Thanks for everyone's help!