[jhdevos]

To add some reasons why you'd want to learn CUDA first: It turns out that simple things are a lot simpler, and take a lot less code, in Cuda than OpenCL. With Cuda, your kernel and host code will be close together in the same file. You'll need a /lot/ less boilerplate than are needed in OpenCL to accomplish even the most simple things. OpenCL exposes you to a lot more concepts, and a lot more extrinsic complexity, than Cuda. All this means just playing around a lot easier to do in Cuda.

Just take a look at some simple examples in both, and you'll quickly see what I mean. Even though I'm a fan of OpenCL because it is available on more platforms, Cuda is a lot better suited as a learning platform.