Ubuntu Feisty (7.04) + Compiz + Thinkpad T41


As some of you may know, I bought a refurbished IBM ThinkPad T41 (2373-5U2, iirc) during fall 2005, and have been dual booting it with Windows XP Professional and Ubuntu Linux. The hard drive is only 40 GB, which I partitioned as:

  • 26.5 GB Windows (NTFS)
  • 5 GB Ubuntu / (ext3)
  • 1 GB swap
  • 4 GB /home (ext3)
  • 3.5 GB unusable/recovery partition

Windows and Visual Studio 2005 Professional managed to eat up about 8 GB, plus another 1.2 GB for the installers I left on the hard drive, and miscellaneous other crap put the Windows partition near its capacity, and I had nearly 1 GB free on the Ubuntu / partition, but when it came time to upgrade to Feisty, I was informed that I needed over 1.1 GiB free. Even after some housecleaning, I still came up short, so I decided to wipe / and perform a fresh Feisty (Ubuntu 7.04) install. I figured I was probably about due anyway, since I’d been dist-upgrading since at least Breezy. The installation went fine (I did it during a meeting here at work), but when I went to enable “Desktop Effects” (compiz), I got some odd results. Actually, immediately after enabling it, the right section of the screen was displaying odd banded/corrupt artifacts (leftovers, I presume, from switching video modes, etc). I disabled the effects for the time being, and went about my life.

Fixing Compiz Display

As I noted above, I had problems getting Compiz working from Ubuntu 7.04 Feisty on my ThinkPad T41 with an ATI Mobility Radeon 7500 (01:00.0 VGA compatible controller: ATI Technologies Inc Radeon Mobility M7 LW [Radeon Mobility 7500]). One or two Ubuntu version ago, I had some OpenGL performance issues with xmoto (a game), which I kind of resolved by changing my xorg.conf file to explicitly use the ‘radeon’ driver instead of ‘ati’ and forcing AGPMode 2 (and maybe something else, I don’t remember for sure). I hoped that would solve my current problem, but alas, it did not. Perhaps resulting from my inability to accurately describe the results I was seeing, I was unable to immediately find any quick fixes to my problem. I guess that’s why it’s still beta, huh?

Update! I reinstalled Feisty (fresh) on my new laptop hard drive, and spent some time isolating the line that fixed the display rendering. It wasn’t the original line I thought, but rather:

Option "AGPSize" "32"

Fixing Compiz Performance

After getting compiz working, I was still getting weird performance hits, where I could hear my hard drive click, whirr, and see CPU spikes during really any display updates (even scrolling a man page in a gnome terminal window would spike the CPU). I thought this was somehow related to the new IDE device handling by the SCSI subsystem, and possibly not having the drive using DMA. I followed that hunch for a while, since it seemed that other people were indeed reporting issues of that nature in Feisty. The information I could glean from dmesg suggested that the drive was in fact in DMA mode, but during the course of the investigation, I noticed some questionable SMART values, so I decided that maybe my hard drive was just dying, and bought a replacement. However, I wasn’t entirely convinced that was the problem, so I kept poking around. I tried many combinations of options, but eventually found a winner. Again, I’m not 100% sure which line was the actual solution, but I think it may have been the following line in my Device section of xorg.conf:

Option "RenderAccel" "true"
Along the way I also modified my dric (/etc/dric or ~/.dric) to enable hyperz as follows (alternatively accomplished with the package driconf):

dric file »

Full xorg.conf Devicesection:

Full xorg.conf Device section »

2 Responses to “Ubuntu Feisty (7.04) + Compiz + Thinkpad T41”

  1. Michel Says:

    Hello, I installed driconf and ran it. Also changed the xorg.conf to this:

    Section “Device”
    Identifier “ATI Technologies Inc Radeon Mobility M6 LY”
    Driver “radeon”
    BusID “PCI:1:0:0”
    Option “DRI” “true”
    Option “AGPSize” “32”

    And now, finally, I got beryl to work without problems on my laptop Compaq Evo N600c. Thanks for your great tip !!

  2. maabaa Says:

    Hi, just got an old Vaio from a friend, with the mobility 7500, and your xorg.conf settings saved me !
    I had a buggy compiz on Feisty and now it works just fine.
    Thanks a lot for sharing your knowledge.

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