a couple of weeks earlier I installed the new catalyst 12.3 driver (actually I downloaded 12.2 but it says I've installed 12.3) and now I get less PPD. It's about 15k. Today I just stopped the CPU folding and my two GPUs continued. Suddenly the PPD grow to 18k (9k per GPU) and as soon as I enable the CPU folding, the PPD drops to 15k again. I also managed out that the CPU usage for each fah-core16 is about 20%.
All clients are set up to advanced. With the catalyst 11.11 driver I had the best performance in games and the PPD was about 28k while folding all clients.