Just my 2 cents, I replaced a 9800pro running @ XT speeds with a Leadtek 6800nu. The 9800pro ran faster. But, I only play LOMAC which is a DX8 sim and is poorly optimized. I've found if I OC my cpu to my unstable point (Barton @ 2.4Ghz), the 6800 just about equals the 9800pro. So, make of that...
BTW, I should have said in my earlier post that my pro had an R360 core, but that still doesn't explain why my 6800 is underperforming from what I expected. If there is something wrong in the setup, I am completely baffled. It's even running 4xAF where the pro was running 8xAF.
I've got shimmering with a 6800, AMD2500+M OC'ed to 3200+, nForce2 chipset.
Has anyone who has it tried to pull the vid card and put it in a different rig? It might help to narrow down the cause of the problem.