<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW - [GEN9] 20% perf drop in windowed/composited GpuTest Triangle" href="https://bugs.freedesktop.org/show_bug.cgi?id=108598#c4">Comment # 4</a> on <a class="bz_bug_link bz_status_NEW " title="NEW - [GEN9] 20% perf drop in windowed/composited GpuTest Triangle" href="https://bugs.freedesktop.org/show_bug.cgi?id=108598">bug 108598</a> from <a class="email" href="mailto:eero.t.tamminen@intel.com" title="Eero Tamminen <eero.t.tamminen@intel.com>"> Eero Tamminen</a> <pre>(In reply to Chris Wilson from <a href="show_bug.cgi?id=108598#c1">comment #1</a>) > That metric may not include the frequency of screen updates, which is the > likely change here in the composited case. My suspicion is that we interject > more work from the xserver resulting in more frames being blitted from > individual batches as opposed to several frames being amalgamated into a > single batch. Just a hunch. Triangle test FPS is *very* high (it does just fast clear and draws half window sized triangle with trivial shader), whereas Compiz updates are limited to monitor frequency. Looking at the collected data: * Compiz updates at 60Hz, that didn't change. * GpuTest glXBufferSwap timing distribution changed so that: - slowest frames are now 7x slower, - fastest frames are 10% faster, - median frames are 1-2% slower, - which results in average FPS being ~20% slower. Maybe kernel reacts now worse to Mesa frame throttling behavior? (Controlled by Mesa "disable_throttling" env var.) If you're interested, I can send you scripts to track & visualize individual buffer swap timings and GPU & CPU speeds.</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the QA Contact for the bug.</li> <li>You are the assignee for the bug.</li> <li>You are on the CC list for the bug.</li> </ul> </body> </html>