My two desktops will be finishing a 31 hour render at around 10:00AM. 4210 @ 24 FPS, 1080p, Blender Cycles, with compositing calculated after each frame. Rendering the last ~450 frames on my slow desktop (3 minutes per frame), and the first part of the animation is rendering on my normal computer (30 seconds per frame). Using GPU for the compute device on my main comp, and despite only being able to run a single thread, it is still so much faster than CPU rendering.
Fun fact: originally, the render time was at 2.5 minutes per frame on my good computer, which would have put me at over 175 hours for the render time, which is more than a week of continuously running my GPU on a single process.