Catalyst 8.8 and poorer performance

[legume]

For anyone seeing slower performance with 8.8 try the "nopat" boot option to disable the use of PAT and see if that helps.

I wonder if there is more to it than just PAT.

I just built a vanilla 2.6.26.3 and

# CONFIG_X86_PAT is not set

but I now see glitching in the ut2004 demo which does not happen with 8-8 on a 2.6.24.2 (whose config was used to build the 26.3).

[lavinog]

Tried the nopat option: little improvement, but still slower than 8-7

glxgears:
8-7: ~2100fps
8-8: ~1500fps
8-8(nopat): ~1680fps

returned to 8-7 and got the 2100fps
also 8-6 yeilded about 2300fps, but was pretty unusable, prior to 8-6 it was consistantly ~2000-2100fps

I know glxgears isn't a true benchmark, but it works for comparing results on the same machine to some extent. Besides I can barely play ut2004 on 8-8 now the frame rate is so bad.

As far as stability: 8-5 and 8-6 segfaulted on just about anything. 8-7 works nicely. 8-8 has crashed my system a couple of times (once on when switching a youtube video from fullscreen, and another time when playing around with gxine's visualations.)

Using:
Ubuntu 8.04 64bit
2.6.24-21-generic #1 SMP Mon Aug 25 16:57:51 UTC 2008 x86_64 GNU/Linux
Gigabyte GA-MA78GM-S2H: (3200 IGP)
AMD AthlonX2 4850e
4g ram