[ldargin]

AMD GPUs have a reputation for speedy integer operations, which are essentially bit-wise operations, so they are often chosen for bitcoin mining. So you might want to consider learning OpenCL, since CUDA runs only on NVidia cards.

[sounds]

I've spent a lot of time using both OpenCL and CUDA, and I would recommend CUDA not because I like NVidia as a company, but because your productivity will be so much higher.

NVidia has really invested into their developer resources. Of course, if your time to write code and debug driver issues isn't that important, then an AMD card using OpenCL might be the right choice.

(I'll try to be honest about my bias against NVidia, so you can more accurately interpret my suggestions. I think along the lines of Linus Torvalds with regard to NVidia... http://www.wired.com/2012/06/nvidia-linus-torvald/ )