nb - are there any simple tutorials that can light me the path to gpu coding easily?
I'm not sure if there are any good top to bottom tutorials. We learned it through projects and documentation. In general, we simplify the GPU code as much as possible, both to make it fast and to avoid branches, loops, etc. Pick your favorite language, find OpenCL bindings, and run some Hello World tutorial. Then pick a project that's embarrassingly parallel (hash searches, noise generation, etc) - each result has no dependence on its neighbor. Read the documentation and pay attention to the memory model. There are a lot of hidden gotchas that can dramatically reduce your performance if you miss them.