title: Timing CUDA operations
body: <p>I need to time a CUDA kernel execution. The Best Practices Guide says that we can use either events or standard timing functions like <code>clock()</code> in Windows. My problem is that using these two functions gives me a totally different result.
  In fact, the result given by events seems to be huge compared to the actual speed in practice.</p>
  
  <p>What I actually need all this for is to be able to predict the running time of a computation by first running a reduced version of it on a smaller data set. Unfortunately, the results of this benchmark are totally unrealistic, being either too optimistic (<code>clock()</code>) or waaaay too pessimistic (events).</p>