Silgrad Tower from the Ashes

I just upgraded my video card from an ATI X1300 pro 256 ddr2 to a Nvidia 8600 256 ddr3. On the X1300 I would get about 20-30 fps with about medium settings, other than resolution changed to 800*600. On the 8600, I have similar settings, but I get an average of 8 fps.
I do have the latest drivers, anyone have any ideas?

I posted this on the BSF, and got a few replies, but nonthing worked yet. I have tried deleting the ini, newest drivers, and used drivercleanerpro to get rid of those left-behind files from the ATI drivers. Any help is apreciated.

Are you running the latest released drivers, or the lastest beta drivers? Is this XP or vista?

Latest non-beta, xp 32-bit.

I wouldn't call going from an Ati card to Nvidia card upgrading

I would.

Nvidia is better but the drivers seem crap now becuase they are working on Vista Ones

I must admit, the AMD/Ati combination is not really doing great at the moment; Nvidia has the better high-end cards ATM. Still, the mid-end cards rock Nvidia's ass off....

I'd take my 7600 over an x1600 any day.

I have the Asus EAX1650 Pro 512 mb DDRII Silent for just 100 euro (~120 dollar) it rocks!

Alright, alright, lets not turn this into a which is better thread, lets try to solve my problem. I think I'm going through Oblivion Withdrawal.

And besides, we all know Nvida will win.