title: nvidia-smi GPU performance measure does not make sense
body: <p>I am using Nvidia GTX Titan X to do deep learning experiment.
  I am using nvidia-smi to monitor the GPU running state, but the perf(ormance) state the tool provided does not make sense.</p>
  
  <p>I have check out the nvidia-smi manual, it said the following:</p>
  
  <blockquote>
    <p>Performance State
           The current performance state for the GPU.  States range from P0 (maximum performance) to P12 (minimum performance).</p>
  </blockquote>
  
  <p>Without running any process on GPU(idle state),the GPU performance state is p0.
  However, when running some computation heavy process, the state became p2.</p>
  
  <p>My question is, why my GPU is at P0 state at idle, but switch to P2 when running heavy computation task? Shouldn't it be the opposite? </p>
  
  <p>Also, is there a way to make my GPU always run at P0 state(maximum performance)?</p>