title: Need to install opencl for CPU and GPU platforms?
body: <p>I have a system with an NVidia graphics card and I'm looking at using openCL to replace openMP for some small on CPU tasks (thanks to <a href="https://stackoverflow.com/questions/4738045/openmp-huge-performance-differences-between-visual-c-2008-and-2010">VS2010 making openMP useless</a>)</p>
  
  <p>Since I have NVidia's opencl SDK installed clGetPlatformIDs() only returns a single platform (NVidia's) and so only a single device (the GPU).</p>
  
  <p>Do I need to also install Intel's openCL sdk to get access to the CPU platform?<br>
  Shouldn't the CPU platform always be available - I mean, how do you NOT have a cpu?<br>
  How do you manage to build against two openCL SDKs simultaneously?</p>