Turning to looking at the Intel integrated graphics performance, we began with GtkPerf to look at the performance of different GTK widgets on the desktop. With GtkComboBox, its performance was incredibly faster in the Intrepid Ibex and Jaunty Jackalope releases.
The GtkDrawingArea - Pixbufs performance was also much faster in the two newer releases. With Ubuntu 9.04 there seems to be a significant regression, but it is still running ahead of where it did in Ubuntu 8.04.2 LTS. If you are a longtime Phoronix reader you will know about all of the invasive work that has been going on within the Linux graphics stack, particularly when it comes to the open-source Intel graphics.
Intel has rolled out the Graphics Execution Manager for providing in-kernel memory management, has adopted the DRI2 stack, and in the Linux 2.6.29 kernel and later it has kernel mode-setting. Particularly because of all the memory management changes, some performance regressions are prevalent with Intel's latest code. Back in January we talked about Intel graphics regressions in Ubuntu 9.04, but fortunately, some of those regressions have since been fixed while there are still definitely a few problems left.
Canonical is defaulting to EXA rather than the UMA acceleration architecture for Intel hardware in Ubuntu 9.04, which does make some things slower, but UXA is rather instable at this time. We also have Intel UXA benchmarks. As of this week, Canonical is looking at fixing some of the performance problems when using EXA with Intel graphics by enabling the greedy migration heuristic by default. This should improve the Intel performance a bit more, but is an interim fix until all of the Intel graphics changes stabilize.