Does changing your Compute Device, change all computes of Blender? So, I have recently moved from using Blender, on my family's Nettop PC, to my personal, gaming PC. And with this move, came to option to use CUDA instead of CPU.

Which leaves the question, if I move to CUDA, does that change all computing, for like physics baking, or only for rendering?

Just a nooby question that I wanted to know, and yes, I know you can specify GPU rendering separately.
Only rendering process can use GPU acceleration, specifically rendering with Cycles Render Engine alone; even switching to Blender internal ignores all benefits of GPU acceleration.

CUDA acceleration is not supported anywhere else in Blender. The only remaining parts, other than the OpenGL Viewport and UI Drawing, that use GPU acceleration (like Open Subdivide evaluation and Compositor OpenCL compute), are unaffected by the CUDA computing device settings, and use their own different settings in specific places.