Maxwell and P2P

I cannot get P2P to work between GTX 980 and Titan X, Ubuntu 10.14 x64, driver version 352.21. On the very same system, I used GTX 780 and 780 Ti without problem, P2P worked. Tried also mixing those two pairs of cards, no success. What am I doing wrong? Or is there some kind of new driver restriction?

Are you asking about CUDA? This post might be more appropriate in one of the CUDA forums.

Oh yes, sorry for that, could U move it please?

The 780 and 780 Ti both use the same GPU (GK110). On the hand the 980 and Titan X use different GPUs (GM204 and GM200, respectively). Peer-to-peer between different GPUs is not generally supported.