free radeon driver settings? (Linux)

[a_grue]

Has anyone managed to get a decent FPS using the free Radeon driver? I'm using HD3850 with 64-bit Ubuntu Karmic, 2.6.33 kernel and the newest free radeon driver . Half of the maps give me a stable 60 FPS (at 1600x1200), but on some I get frequent framerate drop to 30-40 FPS, which is really noticeable, almost unplayable. Is there perhaps an option that needs special tweaking for this driver? Right now I have all the fancy options turned off, including lightmaps, dynamic lightning, antialiasing and particles.

One example of a maps that do this is the CTF version of evilspace.

[Melcar]

HD4850, kernel 2.6.33, radeon packages from xorg-edgers. I can play most of the regular maps with the normal preset at 1680x1050, except for a few like Strength and Starship. Most costume maps work fine as well. No extra settings with the driver. Frames range from 20 to 80 on average.
The driver just isn't fast. 50% slower than fglrx last time I compared the two. Recently I have been experiencing performance regressions in some games as well.

[a_grue]

Do you have KMS (kernel-mode setting) turned on?

One thing that bugs me is that I can't get more than 60 FPS in any game. This usually indicates that sync-to-vblank is turned on. Needless to say, I have it off in the game, and I also tried explicitly disabling it through driconf, with no luck. Tried both with and without a compositing manager (KWin) and turning off vsync flag there. In fglrx, vsync made the game much less responsive, so I wonder if that could be a possible reason for the laggish feel of the game when it drops to 30 FPS (which normally shouldn't feel that bad).

BTW, Quakelive is much more responsive (after you switch off postprocessing), so that hints me that at least part of the problem lies in the game.

[Melcar]

KMS is on. KMS performance is especially bad with 2.6.33 (both 2D and 3D), so you may want to turn it off and see if 3D is a bit smoother (doing so will prevent you from using OpenGL2.0 though). Going back to 2.6.32 could also have a positive effect, though I haven't tried to check. To turn off KMS in 2.6.33 just append to your kernel boot parameter line:

Code: Select all

radeon.modeset=0

[a_grue]

Yep, disabling KMS removes the cap of 60 fps. Still, I get FPS drops on the same maps. I also *think* it feels a bit more responsive. In any case, today I've had a lot more nex hits than for several weeks, perhaps because of that

Another issue that I haven't seen in fglrx: there are wrong textures on one specific map, facing worlds. It looks really funny: the whole ground between the towers is covered by a random texture (each time something different). These are supposedly textures used for other objects (but stretched), not just random noise. Not sure how can it have anything to do with the driver, though.

[Melcar]

The OpenGL code is still not complete, so you're going to get random rendering errors and other oddities. The mesa driver for r6/7xx chips is more unstable than for older chips, since it's seeing a lot of commits these days. Expect lots of regressions and the like. Things should get better in the near future.
Been trying the Lucid alpha and the driver works rather well there. Not faster from what I can see, but less buggy. KMS is also rather fast with the new xserver.