In the CUDA documentation it states.
-Managed allocations are automatically visible to all GPUs in a system via the peer-to-peer capabilities of the GPUs. If peer mappings are not available (for example, between GPUs of different architectures), then the system will fall back to using zero-copy memory in order to guarantee data visibility. This fallback happens automatically, regardless of whether both GPUs are actually used by a program.
When running the simpleP2P example it states that NVIDIA TCC must be enabled. Then when trying to enable TCC on GTX Titan or GTX Titan X it states that it is not supported on these GPU.
So my question if TCC cannot be enabled will managed memory default to zero-copy memory between GPU?
Can unified memory be used across multiple GTX Titan X?
If not is there a way to use P2P on GTX titan?