6800 OC and I'm gettting odd framerate drops

[murasmas]

Athlon64 3500+
ASUS A8V Deluxe
1024 RAM (just so you all know I have enough)
geForce 6800 OC stock (haven't done anything fancy to it yet)

I'm using driver version 7.1.2.0

I'm getting frame rates of 45-138 when I play Counter Strike Source, and I'm wondering why. I notice that in certain parts of Doom 3 I get the same slow down. I play in 1024x768 at high/medium detail, so I don't know why it's giving me grief. My rig should be fast enough not to get frame rate drops.

 

[murasmas]

bump
Also, when I move fast from left to right, somethings start getting blocky, like an oppenents legs. It fragments for a brief second in squarish shapes. I've tried the latest official nVidia drivers and the newer one that I currently have installed, 7.1.2.0

 

[wmansfield]

All background crap (antivirus, etc) turned off? Is your hard drive going crazy during these slowdowns?

 

[murasmas]

yes, this is a clean install. I only have the Steam client running. Now, I have gotten down to 25 FPS in the map "Office" and I think it's because of the stupid ATI/nVidia differences in the cards. Doom3 gives me very little slowdown when it does get intense... darn partial precision floating point calculators.