Folding@home it's very slow speed with Amd 6900, why ?
4000 PPD on Amd 6970, 16000 PPD on Geforce 570 Nvidia...
Amd forum is not compatible with Explorer 9 beta... impossible to edit messages...
Thanks for the explorer compatibility issue. I am not sure what PPD actually constitutes. As such it mentiones that those values may depend on the nature of Work loads scheduled.
The architecture of AMD GPU is quite different than NVIDIA's and one might be better in some cases while other may improve the performance in some other case.
Simple and correct answer for now: Because ATI and nVidia clients run different programs.
Until the OpenCL client it's impossible to try to explain ppd difference by hardware differences, they aren't doing the same work.
there was problem (maybe it is still there) that that their GPU client start fixed number of thread equal to number of compute units. there was compare 3870 vs 4870 that have same performance.