hi m8, i have the same mobo and ram as you but with 6600.i set timings to 4 4 4 12 and 2.3v and set them to 533 in bios then when i put the fsb up to 400 the ram will be at 800, have you tried that way? by the way ive ran them at 1000 with same volts (2.3)but with 5 5 5 15, the only blue screens i get are nv4_disd.dll