I have an AMD graphics card (HD 5830), but the rendering runs on the CPU, because Blender not see my graphics card. I think that it will render faster on the GPU than the CPU.
I waited the final release version of Blender 2.75 and is now sees at once my GPU, but Cycles Render will not start. The message "Loading render kernels (may take a few minutes the first time)" and then appears "OpenCL build failed: errors in console", in a console Error E013: Insufficient Private Resources OpenCl
On my computer, little RAM, 3GB. Device Manager shows that at the time compilation uses all available memory. Maybe 3GB not enough to successfully compile?
Someone you know, there are cases of successful run in cycles of rendering graphics that do not support AMD GCN?
P.S. Maybe in my case worth trying to start already compiled kernel OpenCL?