@Alberts, I'll do some more tests and come up with hard numbers concerning the performance of metacity with or without compositing. I do believe that in some cases it will be possible to optimize the performance through appropriate bug reports and patches; but I also strongly believe that there will be other cases where the different design choices (compositing) will come with an unavoidable performance hit. And while e.g. "3 times slower" may be acceptable in new e.g. core i5 systems, it's not acceptable in new e.g. atom systems. It doesn't affect only old PCs or networked X, it's just that it's more visible there.
@Dmitry and Alberts, what if LTSP users find it necessary to have compositing off by default? (as a local setting in their installations) What issues should they expect from gnome-flashback then? - Harder window resizing due to 1 px border. - Notify-osd notifications ==> I did a quick test and they seem to work; albeit without transparency. Did I miss something? - Decorations ==> Example? I couldn't reproduce it. - Various docks ==> Example? And more significant, how much support should they expect from gnome-flashback developers for the non-compositing case? For example, your support in all the bug reports that I've filed so far was excellent! Does that mean that you won't be willing to do any non-compositing related work at all? Would you be willing to guide persons that are interested in working on such issues? Or to accept patches from them? I understand that gnome-flashback isn't specifically targeting old or networked clients, but does that also mean that it doesn't care at all about that use case? If that's the verdict, then maybe LTSP should evaluate other desktop environments like Mate as the default (I think "marco" defaults to non-compositing in 16.04). No matter the answer(s), I again want to thank you very much guys for all your work! :) -- 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
