Our new 6990x2 Windows 7x64 rig is fluxuating up and down in hash rate.
Yesterday I was getting 1300+ Mhash/s consistently. Now deepbit is telling me I'm getting 938 Mhash/s.
I'm using GUIMiner poclbcm, default settings (only added -v to the first GPU before the drop)
Clock is at 900Mhz. Mem at 1250. Fan set to keep the chips below 95C.

PS What hash rate should I expect out of this baby?