Does anyone know how good the support for this (and similar) card(s) is in the latest versions of all components?
If you use the classic Mesa driver (r600c) + latest X driver + latest kernel:
- OpenGL 2.1
- Profile-based powersaving works well. Dynamic powersaving works, but is glitchy
- Desktop effects work great
- Most games work, see the matrix here: http://www.x.org/wiki/RadeonProgram
- Performance is not fantastic. Things are considerably slower than with the proprietary driver, but playable (I've just finished Doom3 on high quality on my budget $40 card)
With the r600g driver, it should be similar, but somewhat slower and buggier. However, the future development will concentrate on this driver, and it should exceed the classic driver significantly in the future.
Stack reffers to a couple of drivers. There is no such thing as 'One driver to rules them all'. On Windows you also don't install one graphics driver, but a set/stack of drivers, even though you just download what seems to be one driver. You have a DirectX driver, an OpenGL driver, a 2D driver, a video playtback driver, etc.
That's a bit of an awkward/inaccurate explanation of a "stack". I've always understood a "stack" more literally as a pile of things on top of each other and you need to make it through ALL of them before you can meet your objective....
I.e. a single branch within a dependency tree would represent that leaf's stack.... leaf --> parent --> parent's parent --> hardware, etc. That leaf's sibling isn't a member of the same stack. So you've got the mesa stack, you've got the video playback stack, you've got the 2d stack, etc. There are common functions within each of these stacks, but the stacks are separate stacks within the same overall driver architecture.
Real world example....
The "drive a car" stack:
1) you, the driver,
2) the car,
3) the fuel,
4) the gas station,
5) the fuel refinery,
6) the crude,
7) the military
Your neighbor's backup generator stack doesn't involve you or your car, but shares the fuel stack in common.