title: How to adjust the cuda number of block and of thread to get optimal performances
body: <p>I've tested empirically for several values of block and of thread, and the execution time can be greatly reduced with specific values. </p>
  
  <p>I don't see what are the differences between blocks and thread. I figure that it may be that thread in a block have specific cache memory but it's quite fuzzy for me. For the moment, I parallelize my functions in N parts, which are allocated on blocks/threads. </p>
  
  <p>My goal could be to automaticaly adjust the number of blocks and thread regarding to the size of the memory that I've to use. Could it be possible? Thank you.</p>