I am thinking of upgrading my video card and I have looked into this new CUDA technology. While some cards support CUDA, they may under perform your CPU.
Here is what I have found. I could be wrong.
Each CUDA enabled card has at least one multiprocessor made up of 8 processors, with 8192 registers, capable of running 768 threads. Some cards have many multiprocessors and can run many more threads.
Here are some cards with the number of multiprocessors.
The worst:Geforce 9300M GS,9200M GS, 9100M G,8400 M G,
Quadro FX 370M,NVS 130M 1 multiprocessor
:Geforce GeForce 8500 GT, 8400 GS, 8400M GT,9500M G, 9300M G, 8400M GS, 9400 mGPU,9300 mGPU, 8300 mGPU, 8200 mGPU,8100 mGPU
Quadro FX 370, NVS 290, NVS 140M, NVS 135M,FX 360M 2 multiprocessors
GeForce 9500 GT, 8600 GTS, 8600 GT,9700M GT, 9650M GS, 9600M GT, 9600M GS,9500M GS, 8700M GT, 8600M GT, 8600M GS
Quadro FX 1700, FX 570, NVS 320M, FX 1700M,FX 1600M, FX 770M, FX 570M 4 multiprocessors
GeForce 9700M GT
Quadro FX 2700M6 multiprocessors
GeForce 9600 GT, 8800M GTS, 9800M GTS8 multiprocessors
GeForce 8800 GTS,GeForce 9600 GSO, 8800 GS, 8800M GTX,9800M GT
Quadro FX 4600,Quadro FX 3600M12 multiprocessors
GeForce 9800 GT, 8800 GT, 9800M GTX
Quadro FX 370014 multiprocessors
GeForce 9800 GTX, 9800 GTX+, 8800 GTS 512,GeForce 8800 Ultra, 8800 GTX
Quadro FX 5600,Quadro FX 3700M
Tesla C87016 multiprocessors
GeForce 9800 GX2
Quadro Plex 1000 Model IV
Tesla D8702x16 multiprocessors
GeForce GTX 26024 multiprocessors
GeForce GTX 28030 multiprocessors
The Best:Tesla S10704x30 multiprocessors
This is just a rough guide, but shows how different some of the cards are. I'm sure that bandwidth and memory change things as well.
I also read that if your card is in SLI mode you will not benefit from the extra card, so a 9800 GX2 will appear as 16 multiprocessors in SLI mode rather than 32.
Hope this helps.
***edit*** the tesla might be a computer without a cpu rather than a card, I'm not sure.