@Tynach, the symptoms you describe do advocate in favour of the toolchain/optimizations hypothesis. If upstream builds are not affected, wherease Ubuntu builds are, when both are run on the same platform, surely there is a difference in the optimizations used to produce the binary under test.
That said I've tested your sample shader in shadertoy on Ubuntu 21.04, and while the framerate is not super constant it does hit 60FPS regularly (chromium is behaving better, also around 60FPS but with a much more constant framerate than firefox). That's with the firefox Ubuntu build, and the chromium snap. -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to firefox in Ubuntu. https://bugs.launchpad.net/bugs/1908082 Title: Ubuntu Firefox is 15% slower than Flatpak Firefox for speedometer benchmark Status in firefox package in Ubuntu: Incomplete Bug description: Steps to reproduce: I installed Firefox Flatpak (https://flathub.org/apps/details/org.mozilla.firefox) and Chrome. I executed closed all apps and processes and one by one I executed Speedometer test (https://browserbench.org/Speedometer2.0/) in each browser 3 times. I took the max score for reach browser out of the 3 executions of the test. Actual results: Results 100.3 - Firefox Flatpak 85.42 - FIrefox DEB (pre-installd from the store) 100.3 - Google Chrome The preinstalled DEB package Firefox was slower than both Firefox Flatpak and Chrome Expected results: I expected Firefox DEB and Firefox Flatpak to have the same results. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/firefox/+bug/1908082/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp

