NVIDIA 8800 integer performance

There was some discussion here a while ago about the possibility of using GPUs (Graphics Processing Units) to speed up cryptography. NVIDIA recently released some information about the integer performance of their new GeForce 8800 GTX GPU. It seems to be the first mass market GPU that can do 32-bit integer multiplications, and they take 8 cycles each according to the specs. [1] The 8800 GTX has 128 ALUs running at 675 MHz.

I seem to recall that a 120 MHz Pentium could do a 32-bit multiplication in 10 cycles, and about 10 1024-bit RSA decryptions per second. GeForce 8800 GTX seems to be roughly 700 times as fast, so maybe it can do 7000 1024-bit RSA decryptions per second. By comparison, a 2.4 GHz Intel Core 2 Quad in 64-bit mode can do 6000 1024-bit RSA decryptions per second when using all four cores. [2]

This seems rather disappointing since I was expecting a big jump in performance from all the hype about GPGPU/stream computing. Anyone want to sanity check my numbers and see if I dropped a zero somewhere?

[1] http://developer.download.nvidia.com/compute/cuda/0_8/NVIDIA_CUDA_Programming_Guide_0.8.pdf
[2] http://libtomcrypt.com/ltc113.html

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