We just installed GeForce GTX 470 on a machine with Core2Duo 2.33GHz and 2.5GB of RAM.
NSight plugin is installed on VS08. Now I try to do a simple job of moving 768MB (I tried different sizes too) to the GPU and then back to host. With the NSight Memory profiler, I really get shocking results. H2D peak bandwidth of just around 1.7GB/s and around 1.1GB/s for copying back to host memory. There is no kernel call in the code just memory copies.
Theoretically we can achieve around 65GB/s peak bandwidth (320bits/cycle, 1674M cycles/sec). Is it just me or am doing something wrong?
I have attached the screen shot of profiler results and also the simple code.