Adding INTEL_DEBUG=perf to /etc/environment has seemingly explained the problems. Atoms are falling back to software rendering(!), which is theoretically easy to avoid. Here's a summary of what I get in unity8.log on an Atom N270:
PROBLEM: old_intel_miptree_blit: Can't use hardware blitter from MESA_FORMAT_B8G8R8A8_UNORM to MESA_FORMAT_A_UNORM8, falling back. intelCopyTexSubImage - fallback to swrast CAUSE: Unknown PROBLEM: i915_program_error: Exceeded max ALU instructions (76 out of 64) ENTER FALLBACK 10000: Program CAUSE: GLSL shaders are approximately 18% larger than the hardware supports. PROBLEM: ENTER FALLBACK 10000: Program LEAVE FALLBACK Program [PERFORMANCE]: Last frame took 2643 ms to render. CAUSE: Same as previous issue. Reused a program that ran in software. Interestingly mir_demo_client_eglplasma has the same issues (bug 1583532) but it sounds like that's easily fixable. -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to unity8 in Ubuntu. https://bugs.launchpad.net/bugs/1580792 Title: Unity8 on Intel Atoms performs poorly Status in unity8 package in Ubuntu: Confirmed Bug description: (problem forked from bug 1549455) Unity8 on Intel Pineview performs very poorly. Frame times appears to be up to 900ms, Qt's renderer thread using 100% CPU. Running unity8 with MESA_DEBUG=1 EGL_LOG_LEVEL=debug reveals a few MESA errors: http://paste.ubuntu.com/16344427/ Quoting @vanvugt "Those Mesa errors "Mesa: User error:" all look like OpenGL features that Unity8 is hitting but mir-demos don't. So those gl calls are also good candidates for explaining poor performance, especially if Mesa is falling back to software rendering for them." Since Qt tends to perform just fine on that hardware in X11, something isn't right. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/unity8/+bug/1580792/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
