title: How to measure the amount of data copied in NVIDIA nsight systems?
body: <p><strong>Trivia</strong></p>
  <p>In NVIDIA Nsight Systems you can use the <code>--stats=true</code> flag to get the details for data transfer between GPU and CPU. The output includes a section similar to what follows:</p>
  <pre class="lang-sh prettyprint-override"><code>CUDA Memory Operation Statistics (KiB)
  
                Total      Operations              Average            Minimum              Maximum  Name                                                                            
  -------------------  --------------  -------------------  -----------------  -------------------  -------------------
             8192.000               2             4096.000           4096.000             4096.000  [CUDA memcpy HtoD]                                                              
           528384.000               2           264192.000           4096.000           524288.000  [CUDA memcpy DtoD] 
  </code></pre>
  <p><strong>Question</strong></p>
  <p>Is it possible to get this statistics per API call? That is, can we get the amount of data transferred between Host/Device in each of the <code>cudaMemCpyxxx</code> calls?</p>