I'm having an issue mining scrypt with two GPU's: every time I start cudaMiner, one of them (not always the same) seems to return results which mostly doesn't validate. This is tested on Linux, using cudaMiner master, tested both on Z14x14 and T14x32. When I mine using a single card (selected with -d) all results validate... Any idea?
this is a long shot: Would it help to downgrade the video driver to the exact version hat shipped with the CUDA 5.5 toolkit download from nVidia? Of course if your video cards are newer than this driver release, this is a no-go, as the driver would not recognize them ;-/
I'm using the NVIDIA drivers from the Debian repositories, so downgrading isn't that easy... That said, I'm currently using the 319 driver series, which seems like the earliest one supported by CUDA 5.5. I've tried upgrading to the 331 driver series, but that doesn't change a thing.