Thanks for the help. Yeah I have run both the Radeon 5870 and the GTX285 seperately with OpenCL. It's just AMD caps me at only using one UAV buffer at 256 megabytes which is not nearly enough for the datasets I am working with. I own the 2GB version of the GTX285 and Nvidia allows me to run OpenCL/CUDA applications using all 2GB along with the OpenCL implementation being much more mature. It will also be nice to have a dedicated compute card with the GTX285 because this will allieviate my computer from crashing when a kernel has a runtime error and having the video flicker and possibly blue screen out.