Test all device pairings for peer-to-peer memory access support.

peer.cu

#include <stdio.h>
#include <cuda.h>

int main(int argc, char** argv)
{
  cuInit(0);
  
  int count;

  cuDeviceGetCount(&count);

  for (int ii=0; ii<count; ii++)
    {
      CUdevice dev0;
      char     devName0[16];
      
      cuDeviceGet(&dev0,ii);
      cuDeviceGetName(devName0,16,dev0);

      for (int jj=0; jj<count; jj++)
        {
          if (jj == ii)
            continue;

          CUdevice dev1;
          char     devName1[16];
          
          cuDeviceGet(&dev1,jj);
          cuDeviceGetName(devName1,16,dev1);

          int canAccess;

          cuDeviceCanAccessPeer(&canAccess,dev0,dev1);

          const char* const tf = (canAccess == 0) ? "FALSE" : "TRUE";
        
          printf("%-16s  <--  %-16s  :  %s\n",devName0,devName1,tf);
        }
    }

  return 0;
}

Compiled with: nvcc peer.cu cuda.lib -o peer