Can I use GPUDirect v2 - Peer-to-Peer communication on a single PCIe-Bus?:
In general, if you want to find out if GPUDirect Peer to Peer is supported between two GPUs, you can run the simple P2P CUDA sample code or in your own code, you can test the availability with the cudaCanAccessPeer runtime API call
Note that in general, P2P support may vary by GPU or GPU family. The ability to run P2P on one GPU type or GPU family does not necessarily indicate it will work on another GPU type or family, even in the same system/setup. The final determinant of GPU P2P support are the tools provided that query the runtime via cudaDeviceCanAccessPeer. P2P support can vary by system and other factors as well. No statements made here are a guarantee of P2P support for any particular GPU in any particular setup.