Question for folks using the DFI Nforce4 Board with opterons

[datwater]

Hi. I have an opteron 146 CABYE on a biostar nforce 4 board and 2 x 512mb corsair xms. It oc'd very nicely, hitting 2.8 easily on air with stock voltage. Primed and all was well. I just added another matched pair of 2 x 512mb corsair xms, and expected I'd have to slow the ram down some with all 4 slots full, but I am not even stable at 2.5 with a 166 or even 133 divider now, whereas before, with 2 x 512, I could get 250-260 out of the ram no problem without using a divider. So I'm trying to find out if anyone here uses that DFI board everyone likes, with an opteron AND populates all 4 dimm slots. If so, what are your results? I guess I need to decide if I'd rather switch boards, or swap out 4 x 512 for 2 x 1gb. Thanks for any input.