title: Threads and Thread Groups on the GPU
body: <p>I'm wondering about the "grids" of threads/thread groups I can dispatch on the GPU. I'm using Direct Compute so I'll give a concrete example using that API. For example, if I call Dispatch(2,2,2), I understand it dispatches 2x2x2 = 8 thread groups in total. However, what's the difference if I call Dispatch(8,1,1), which also dispatches 8x1x1 = 8 thread groups? Is there any performance difference?</p>
  
  <p>P.S. same question with threads on the GPU. What's the difference between numthreads(2,2,2) and numthreads(8,1,1), declared in the compute (.hlsl) file?</p>
  
  <p>Any help would be appreciated.</p>