title: How to manage large 2D FFTs in cuda
body: <p>I have succesfully written some CUDA FFT code that does a 2D convolution of an image, as well as some other calculations. </p>
  
  <p>How do I go about figuring out what the largest FFT's I can run are? It seems to be that a plan for a 2D R2C convolution takes 2x the image size, and another 2x the image size for the C2R. This seems like a lot of overhead! </p>
  
  <p>Also, it seems like most of the benchmarks and such are for relatively small FFTs..why is this? It seems like for large images, I am going to quickly run out of memory. How is this typically handled? Can you perform an FFT convolution on a tile of an image and combine those results, and expect it to be the same as if I had run a 2D FFT on the entire image?</p>
  
  <p>Thanks for answering these questions</p>