Hi there, I have two questions:
First question: I need to transfer data from GPU to CPU and CPU to GPU. To compute the transfer rate I'm timing the transfers using OpenCL Events; It looks like the transfer from GPU to CPU is faster than the transfer from CPU to GPU (12.2GB/s vs 11GB/s). I read somewhere that this behavior is normal, but don't know why: is it because restrictions imposed by the PCIe or the GPU ?. Any explanation and links will be useful. BTW: I'm using a NVidia C2070 GPU and a PCIe x16 2nd Generation; and the buffer at the host is pinned memory
Second question is: What I actually need is to transfer data from GPU1 to GPU2, so I'm transferring by doing 2 transfers: GPU-CPU and then CPU-GPU using pinned memory. Is there any way to transfer GPU-GPU directly ?. Both GPUs are C2070.