Richard, yes those bar charts indicate there is performance regressions, but that's nothing we don't already know. Unfortunately the author didn't gather Xorg.0.log, glxinfo, xdpyinfo, or other data which could help in investigating the problem.
For those of you looking at glxgears fps, you're going to get a rude shock pretty soon. You've heard that glxgears is not a benchmark. It measures the blitting speed of writing a pixmap to the graphics buffer. Well, video monitors display that data at a limited rate (your refresh rate in fact). Most monitors display at a rate of 60-100 Hz (essentially 60-100 fps). So when you see glxgears saying it is writing frames at 800 FPS, well probably 700 of those frames never even get to the monitor, and thus are just a waste of electricity. Cleverly, upstream is now synchronizing the blitting speed to the monitor's refresh rate, so that it writes only as fast as the monitor can display. So you should see your glxgears FPS values drop down to something nearly equaling your monitor refresh rate. ;-) ** Description changed: I experience significant performance loss with ubuntu 8.10 alpha 3 with my Intel DG965WH based system and SVDO/ADD2 video card. Actually, the performance loss started with ubuntu 8.04.1; I upgraded to see if there was any performance gain with the new version. While "glxgears" produced values between 1580 fps and 1496 fps with ubuntu 7.04 and 7.10, respectively, now I can only achieve something like 445 fps with ubuntu 8.10 alpha 3. I get an error message when starting glxgears that "TTM" was not available and classic mode would be used. Similary, the flight simulator "flightgear" achieves frames rates of 1-2 fps only. My suspicion is that some of the hardware acceleration features of the X3000 system are not being used, and I don't know how to activate them with the new xorg.conf structure and the underlying automatic configuration approach. I would like to see the graphics performance go back to the values achieved in ubuntu 7.04 and 7.10. Your help / comment is greatly appreciated. Bingo [Update] Intel upstream has been in a multi-year effort to rearchitect X and the Intel 2D and 3D driver to provide better performance. While this work is underway, people are seeing variations in performance levels from version to version, for a variety of reasons. There are probably multiple unrelated bugs being reported to this bug report. It is important to note and remember that glxgears is *not* a benchmark tool. It simply measures how fast the driver writes images to the screen, whereas most 3D applications are limited by render speed, not merely blit speed. Instead use a 3D game (flightgear, tremulous, etc.) that has a real rendering workload to make comparisons. - If you're definitely seeing performance problems, please do not comment - onto this bug report - it's too lengthy and rambling already, and your - issue will just be lost in the noise. Instead, make a new report and - please be as specific as possible with exact steps to reproduce and as - much detail and logs as you can. See http://wiki.ubuntu.com/X/Reporting - for tips on making a good X bug report. + If you're definitely seeing performance problems and are able to narrow + it to a specific cause, please do not comment onto this bug report - + it's too lengthy and rambling already, and your issue will just be lost + in the noise. Instead, make a new report and please be as specific as + possible with exact steps to reproduce and as much detail and logs as + you can. See http://wiki.ubuntu.com/X/Reporting for tips on making a + good X bug report. -- [i965, etc.] Poor graphics performance on Intel https://bugs.launchpad.net/bugs/252094 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
