GPU libraries provide an easy way to accelerate applications without writing any GPU-specific code. With the new CUDA 5.5 version of the NVIDIA CUFFT Fast Fourier Transform library, FFT acceleration gets even easier, with new support for the popular FFTW API. It is now extremely simple for developers to accelerate existing FFTW library calls on the GPU, sometimes with no code changes! By simply changing the linker command line to link the CUFFT library instead of the FFTW library, you can take advantage of the GPU with only a re-link. In today’s CUDACast, we take a simple application that uses the standard FFTW library, and accelerate the function calls on the GPU by simply changing which library we link. In fact, the only code change we will make is to use the cufftw.h header file. This ensures that, at compile time, we are not calling any unsupported functions.