The reference design 680i boards as used by evga, bfg were pretty poor. Ok for clocking dual core chips but rubbish with quads. I had the updated a1 revision of the evga 680i. Supposedly better with quads. But still couldnt get much of an oc out of a q6600. Same chip hit 3.8ghz pretty easily in an intel p45 chipset board. North bridge chipset also ran very hot on the 680. Was very common to see people replacing the paste that came on them as it was quite poor and very badly applied.