After updating from .911-r1 to .912, I see a very large decrease in performance. Specifically, in Xonotic 0.7.0, what runs at a full framerate of 60 fps with .911-r1 slows down to 20-30 fps with .912. Reproducible: Always Steps to Reproduce: 1. Run a timedemo of e.g. the-big-keybench in Xonotic 0.7.0 with settings just low enough to allow it to mostly play at full framerate under .911-r1. 2. Run the same timedemo with the same settings under .912 Actual Results: With .912, the performance seems to be fine for the first few seconds of playback, but then suddenly drops to less than half of the expected framerate. Expected Results: Performance should stay about the same as previously. Results of a timedemo under .911 and .912 respectively: 10510 frames 175.4414971 seconds 59.9060096 fps, one-second fps min/avg/max: 55 60 61 (336 seconds) 10510 frames 385.4060950 seconds 27.2699372 fps, one-second fps min/avg/max: 19 29 62 (336 seconds) This was done with a resolution of 2560x1440, 4xAA, 60 Hz refresh rate, vsync, windowed (fullscreen by WM). CPU: Intel(R) Core(TM) i7-4750HQ Integrated Graphics Chipset: Intel(R) Iris(TM) Pro Graphics 5200 kernel version: Linux 3.15.7-hardened (also tried 3.13.10-hardened) window manager: x11-wm/i3-4.7.2 (no compositor) media-libs/mesa-10.2.4 (also 10.0.4 and 9.2.5-r1) x11-base/xorg-server-1.15.0 (also 1.14.5) In addition to x11-drivers/xf86-video-intel-2.99.912, I also tried .912-r1 and .914 with no improvement.
I think it's very likely this is fixed in a new version of the driver. If it's not, please file a bug upstream at bugs.freedesktop.org. We're not prepared to fix driver issues that aren't fixed upstream.