Since the second generation of the GPU client of Folding@Home now supports Nvidia graphics cards, PCGH made some benchmarks.
To receive exact results we did not rely on the Fahmon, but instead calculated the points per day (PPD) using the client's logfiles. During the benchmarks the client calculated packages of the Project 5000, which rewards 98 pinots per workunit.
The range of graphics cards covers (nearly) the whole product variety of Nvidia: starting with the Geforce 8600 GTS, which delivers 1,839 points per day and ending with an overclocked GTX 280 from Zotac, which delivers 7.224 points.
Naturally Folding@Home depends on the shader performance of the graphics card. A big amount of shading processors with high clock speeds, can achieve more than a generally overclocked card.