title: Kernels not running concurrently in CUDA
body: <p>I have a kernel that runs on my GPU (GeForce 690) and uses a single block.  It runs in about <code>160</code> microseconds.  My plan is to launch <code>8</code> of these kernels separately, each of which only uses a single block, so each would run on a separate SM, and then they'd all run concurrently, hopefully in about <code>160</code> microseconds.</p>
  
  <p>However, when I do that, the total time increases linearly with each kernel: <code>320</code> microseconds if I run <code>2</code> kernels, about <code>490</code> microseconds for <code>3</code> kernels, etc.</p>
  
  <p>My question: Do I need to set any flag somewhere to get these kernels to run concurrently?  Or do I have to do something that isn't obvious?</p>