The CUDA library provides a direct, general purpose C-like SPMD programming model for NVIDIA graphics cards (G8x series onwards). This is a collection of bindings to allow you to call and control, although not write, such functions from Haskell-land. You will need to install the CUDA driver and developer toolkit.
http://developer.nvidia.com/cuda-downloads
The configure script will look for your CUDA installation in the standard
places, and if the nvcc compiler is found in your PATH, relative to that.