Hello. I've been investigating white papers, podcasts, etc. on OpenCL and have read some papers on GPGPU development in general, but have not yet found an answer to one burning question. Surely it is feasible to have one GPU take care of both hardware accelerated rendering and GPGPU calculations, but would performance be adequate? Is it a better idea to have two GPUs in a system and keep these concerns separate? How do most people approach this situation? I'm in the research phase of a master's project and am concerned whether or not I will have to drop a load of cash on a machine capable of two solid graphics cards or not.

Any thoughts and knowledge on this topic would be greatly appreciated.