Thank you Its very enlightening - 15-25% usage on a 1080p h.264 encode, minetest takes 30-40%, FreeDoom 20-30%, idle desktop with 2* 1920x1200 0-3%, with a Radeon 4870 graphics card - i.e. nowhere near using the card, yet in minetest's case things are considered 'GPU limited'.

Just yesterday I got kernel v3.9 with Debian Testing, I guess when Mesa goes to v9.2 I can finally move from Open GL 2.1 -> 3.1 or 3.3. Will be very interesting to see if minetest fps goes up, I can finally use the best VPU plugin with pcsx2, and what radeontop says about all this.