I’m having a i7 980x cpu connected to a Tesla S1070 (has 4 gpu’s). I’m transferring data from CPU to each GPU at the same time and trying to measure the bandwidth that I can get between individual CPU-GPU.
The obtained transfer rates between the CPU and the 4 GPU are 0.772456, 0.764574, 2.54562 and 2.5455 GB/s.
But when I just transferred data from CPU to just one GPU the obtained transfer rate is 1.56321 GB/s.
I see that
- when I transfer data from CPU to all GPU’s at the same time the transfer rate is almost 4 * (transfer rate between CPU and one GPU).
- The transfer rate between CPU-GPU in a simultaneous transfer from CPU to all GPU’s can be more than a transfer rate for a CPU to single GPU.
Are my observations correct…?
For the above experiment I proceeded like this..
I associated one CPU thread to one GPU (Tesla C1060) and the sudo code for the thread is shown below.
Pthread_barrier_wait() // to initiate the transfers at the same time.
M. Kiran Kumar.