> @Alberts, I'll do some more tests and come up with hard numbers concerning the performance of metacity with or without compositing.
I did some benchmarks and reported them in https://bugs.launchpad.net/ubuntu/+source/metacity/+bug/1566157 Now I'm more convinced that metacity's compositing-manager should be false by default. For LTSP users, I'll document how to create a /usr/local/bin/metacity wrapper that launches `metacity --no-composite`. Quoting my conclusions from that bug report: I really think that the user's choices would be: 1) compiz, for every PC that supports it, 2) metacity --no-composite, for any PC that doesn't support compiz and that isn't able to spare 50%-80% of their FPS, 3) metacity --composite, ONLY for the minority of the PCs with graphics cards that can't run compiz and with so awesome CPUs that can spare 50-80% of their FPS. If you can find an example of such a PC, please let me know, currently I don't know of any. I do know of thousands of examples in category (2) though. Since `metacity --composite` is so much slower, affecting all apps and actions from simple drawing to scrolling to moving around windows to watching videos to game playing etc, I'd like to again ask you to consider NOT making (3) the preferred session for gnome-flashback for 16.04. I.e. gnome-flashback-compiz could be the default (proposed one), and gnome-flashback-metacity the non composited version, with the --composite option only available as a gsetting for the minority of the people that would need it. Thanks! -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to metacity in Ubuntu. https://bugs.launchpad.net/bugs/1565640 Title: Set compositing-manager=false by default Status in metacity package in Ubuntu: Won't Fix Bug description: In Ubuntu 12.04 and 14.04, metacity's compositing-manager was false by default. In 16.04, it's been set to true. I tried to pinpoint the advantages vs the disadvantages of that, and currently I've only seen disadvantages. I was testing with: gsettings set org.gnome.metacity compositing-manager false (or metacity --no-composite) versus: gsettings set org.gnome.metacity compositing-manager true (or metacity --composite) Speed: the speed for window drawing and moving around is 3-5 times slower when compositing is enabled. This is rather visible locally on old computers, but it becomes a real problem when Xorg is used over the network, like for example in LTSP thin clients. There, dragging around a window draws it in slow motion a whole lot behind the mouse, like a trail, while with compositing disabled, everything is lightning fast. RAM: xrestop shows that with a couple of windows open, metacity now needs 10 MB more RAM. This value increases with the number of open windows. Vsync: in most cases vsync was broken with or without compositing (while with compiz it's working much better). I tried with youtube videos, with VLC etc. The only difference I saw is that with some SDL games like teeworlds, vsync was working with compositing disabled, and was broken with compositing enabled. So my personal results is that metacity's compositing-manager=true doesn't have any advantage currently, and that it makes old client and LTSP client performance a whole lot worse. And unfortunately those are exactly the cases where we prefer gnome-session-flashback instead of e.g. Unity. Therefore I'd like to ask you to consider disabling it by default like it was in the past. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/metacity/+bug/1565640/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp
