title: Multiply one fixed matrix by a huge number of vectors
body: <p>I'll need to change the basis of some 10^7 vectors, each having
  200 coordinates.  So I will multiply one [200 x 200] matrix by 10^7 [200 x 1] vectors. I need it to run very fast but I need to code it fast (one day or less)
  and my CUDA is poor, so I don't want to code it from scratch in CUDA or OpenCL.  Maybe some existing library can do it for me?  Notice that, if the solution uses GPGPU, the matrix should be transfered to the GPU only once, otherwise the performance will be poor.  Could I could use OpenACC (or OpenMP, I don't know)? Is it possible to do this in a day?</p>
  
  <p>I prefer open source solutions (for both convenience and ethical reasons) but I can tolerate a closed source solution, even paid (assuming it is not too costly).</p>
  
  <p>This is for my dissertation.
  Thank you for your attention.</p>