8800gt problems

More info please!
It could be a overheating GPU causing throttling.
There could be a lot of background programs.
Your 8800GT could be underclocked.
I can't really tell with that info, have you tried reinstalling the card and drivers?

From the amount of info provided, I reckon your problems are being caused by solar flares, or tectonic movements but most likely flares.

I have an 8800gt and it gets angry at half life 2, runs 40-60 fps, but it runs CS source at like 140 so idk

Mmmm ive played HL2 for many many hours with my q6600, 4 gb ram, 8800gt 600/900/1500 (stock) with blistering performance in excess of 100fps but to be honest get vsync on me boy, its there for a reason, should help slightly with temps too.

theres really no point trying to get games running at 80+ fps, its a waste, if its locked at 60 or 75 or whatever gameplay will be smoother.

At 60 fps the human eye cant detect frames changing however if your fps is spiking from 40 up to 120 the human eye CAN detect these fps jumps, giving the perception of s*it performance.

Are your in game settings feasible? the 8800gt is good....for the money, but theres a lot of ppl who overestimate what they can handle. Any AA? Max textures? Need more info dude.

Of course you havent really given much in the way of rig specs so you could be using a 8 yr old processor..........bottle(cough)neck(cough) ^^

A nice gpu is not all it takes to have a nice rig.

grab GPU-Z, and check the gpu temp, then check the core clock speed. If its under clocked, you may have an under powerd psu (vista should say something about that on boot up)

It could be almost anything causething the problem. More info needed.

Bang on +1

Thats the technical version of what I said