BTW, I tried the radeon_hd (after adding my 4870 IDs) + its radeon_hd.accelerant. It didn't crash but the display mode was out f sync. Then I searched how and where the accelerant DPrintf() traces are visible and can't find them. Then I run out of free time ;-) For the next free time slot, could you tell me how to see these traces? Thanks. Philippe.