I am more or less understanding of performance amongst the NVidia offerings, between the 680s, Titans, and 770s, but does anyone have experience running Radeon offerings. I'm looking specifically at the 7990, which on paper matches or beats the Titan and comes in cheaper to boot. It eats more power but that doesn't really matter to me as much.
Where CUDA was developed first before Open CL and has far more memory management refinement time, Cuda performance is better and often far less buggy. I would not suggest any ATI over the Titan for GPU acceleration.