I'm now using Ubuntu 9.04 on my x61t. GLXgears now reports varying amounts in the range 900 to 1150 without any mucking with MTRRs. That suggests that the Intel X video driver now uses the PAT mechanism. Good!
The MTRRs are still overlapping. I had to change mtrr-uncover to deal with a gratuitous change made to the format of /proc/mtrr in kernel 2.6.28. You can get the newer version at ftp://ftp.cs.utoronto.ca/pub/hugh/mtrr-uncover-2009may13.tgz Interestingly, fixing the MTRRs with mtrr-uncover and restarting X seemed to make glxgears run consistently at about 900. I have no idea why. Adding "enable_mtrr_cleanup" flag to the appropriate "kernel" line(s) in your /boot/grub/menu.lst will also attempt to eliminate overlapping MTRRs. I don't know which Ubuntu kernel first included the cleanup code but it is in Jaunty's 2.6.28. On my system, the performance effect is the same as if you used mtrr-uncover. Of course it only operates at boot time. There have been obscure cases where mtrr-uncover worked and enable_mtrr_cleanup did not. -- MTRRs set up incorrectly with 4GB RAM -> X slow https://bugs.launchpad.net/bugs/210780 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
