I have created a demo program running on Windows. This program does a simple N^2 force calculation between particles and integrates orbit of the particle system. After running the program, it show a performance result in Gflops (note I count 38 flops per one-force-evaluation, this may be different from other work).
Very interesting demo indeed. Actually the first demo I ran since I changed from Nvidia back to ATI/AMD. I am starting to learn GPGPU-programming and found your example "simple enough", do you mind sharing your sourcecode? I would really appreciate it.