So far, a quick attempt with a Maximus Formula modded to Rampage 0308, I was only able to reach 8x440. 8x450 resulted in DET DRAM or freeze just at OS loading. 8x440 is rock stable overnight with folding and temps is great (everything is watercooled minus my SB, which have a Enzotech low-profile heatsink with a 120mm fan blowing thru).