When I first bought my evga 780i (soon after its retail release), I was running it orthos 12 hr stable at 1800 fsb bus with memory linked and synced. I was using 4x1gb sticks of crucial ballistix (the good ones with the memory chips on both sides of the PCB) at 2.1v.
I shelved it for a while to tinker with an intel chipset board, and recently hooked it back up to my watercooling setup and flashed to the p03 bios. I tried to run 2x2gb gskill 1066 sticks in it (which work fine in another mobo), and I can't seem to get anything stable over 1600 fsb. I wonder if the 780i isn't as fond of the 2gb ram sticks, or if the p03 bios has something to do with it?