title: Running OpenCL on hardware from mixed vendors
body: <p>I've been playing with the ATI OpenCL implementation in their Stream 2.0 beta. The OpenCL in the current beta only uses the CPU for now, the next version is supposed to support GPU kernels. I downloaded Stream because I have an ATI GPU in my work machine.</p>
  
  <p>I write software that would benefit hugely from gains by using the GPU. However this software runs on customer machines, I don't have the luxury (as many scientific computing environments have) to choose the exact hardware to develop for, and optimize for that. So my question is, if I distribute the ATI OpenCL implementation with my application, will that mean it will never be able to use e.g. NVidia video cards?  And if I use the NVidia OpenCL SDK, that it will never run optimally on AMD chips (considering the ATI/AMD link)?</p>
  
  <p>On other words, who is in the end responsible for providing the OpenCL implementation? Will users be able to e.g. install an OpenCL 'driver' for their NVidia video card, alongside a 'driver' that gives them optimal performance on their AMD CPU?</p>
  
  <p>As an aside, are there any good/active support forums for OpenCL apart from the Khronos message boards, or is that the place to go? I've seen that ATI has a board, and NVidia presumably has their own, where does the OpenCL user/developer community hang out? Has it already consolidated into one place?</p>