My OpenArena 0.8.8 benchmark results!
I tested 2 resolutions. 1440x900 uses unoptimized MSAA because of a limitation in my hardware (see here for detailed information - the patch was committed today). 1280x720 is fully optimized, so the hardware runs at full speed.
Code:
Resolution: 1440x900
No AA: 62 fps
2x MSAA: 49 fps
4x MSAA: 35 fps
6x MSAA: 27 fps
2x MLAA: 38 fps
4x MLAA: 38 fps
6x MLAA: 37 fps
It's in line with what I would expect. MLAA seems to have a fixed cost, while MSAA varies depending on the MSAA mode.
Code:
Resolution: 1280x720
No AA: 77 fps
2x MSAA: 65 fps
4x MSAA: 57 fps
6x MSAA: 56 fps
2x MLAA: 49 fps
4x MLAA: 49 fps
8x MLAA: 47 fps
The cost of MSAA is much lower at this resolution thanks to the MSAA optimizations being enabled by the driver, and it even outperfomed MLAA. 6x MSAA is almost as fast as 4x MSAA, which makes sense if I consider how the optimizations work. Of course, it always depends on the app.
System info: ATI Mobility Radeon X1700, Ubuntu 12.10, Linux kernel 3.8.0-rc3, Mesa git, Xfce4, no compositing.