On Ubuntu MATE 16.04 one can select 4 compositing modes via MATE Tweak (german translation):
1. Marco (kein Komposit)
2. Marco (Programmkomposit)
3. Marco (Compton GPU-Komposit)
4. Compiz (anspruchsvolle Schreibtischeffekte mit GPU-Beschleunigung)
On my PowerMac7,3 G5 with a Radeon 9650 Pro only the 1st one works properly. The 2nd one works, but more sluggish and a jerkier mouse pointer. 3 and 4 trash the desktop showing wrong colours. Only VERY jerky mouse movement is possible then. The desktop is no longer in a usable state any longer, you can't click on anything. Restarting the desktop with "systemctl restart lightdm" from console returns the desktop usable (defaulting to 1st compositor.
ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: xorg 1:7.7+13ubuntu3
ProcVersionSignature: Ubuntu 4.4.0-21.37-powerpc64-smp 4.4.6
Uname: Linux 4.4.0-21-powerpc64-smp ppc64
ApportVersion: 2.20.1-0ubuntu2
Architecture: powerpc
CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CompositorRunning: None
Date: Tue Apr 26 23:40:25 2016
DistUpgraded: Fresh install
DistroCodename: xenial
DistroVariant: ubuntu
ExtraDebuggingInterest: Yes, including running git bisection searches
GraphicsCard:
Advanced Micro Devices, Inc. [AMD/ATI] RV350 [Radeon 9550/9600/X1050 Series] [1002:4150] (prog-if 00 [VGA controller])
Subsystem: Advanced Micro Devices, Inc. [AMD/ATI] RV350 [Radeon 9550/9600/X1050 Series] [1002:4150]
InstallationDate: Installed on 2016-03-26 (31 days ago)
InstallationMedia: Ubuntu-MATE 16.04 LTS "Xenial Xerus" - Beta powerpc (20160326)
ProcEnviron:
LANGUAGE=de_AT:de
TERM=xterm
PATH=(custom, no user)
LANG=de_AT.UTF-8
SHELL=/bin/bash
ProcKernelCmdLine: root=UUID=d6fab932-3e79-4f5c-a392-c86c01b5a8f9 ro rootflags=subvol=@ radeon.agpmode=-1
SourcePackage: xorg
UpgradeStatus: No upgrade log present (probably fresh install)
version.compiz: compiz 1:0.9.12.2+16.04.20160415-0ubuntu1
version.libdrm2: libdrm2 2.4.67-1
version.libgl1-mesa-dri: libgl1-mesa-dri 11.2.0-1ubuntu2
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 11.2.0-1ubuntu2
version.xserver-xorg-core: xserver-xorg-core 2:1.18.3-1ubuntu2
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.10.1-1ubuntu2
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:7.7.0-1
version.xserver-xorg-video-intel: xserver-xorg-video-intel N/A
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.12-1build2
xserver.bootTime: Tue Apr 26 22:55:40 2016
xserver.configfile: /etc/X11/xorg.conf
xserver.devices:
input Logitech G100s Optical Gaming Mouse MOUSE, id 6
input HID 046a:010d KEYBOARD, id 7
input HID 046a:010d KEYBOARD, id 8
input PMU KEYBOARD, id 9
xserver.errors:
xserver.logfile: /var/log/Xorg.0.log
xserver.version: 2:1.18.3-1ubuntu2
xserver.video_driver: radeon
ernsteiswuerfel, thank you for reporting this and helping make Ubuntu better.
1) To clarify, you have which mac precisely from the list in https:/
2) Is there something missing when you choose 1 that you don't get from the other three?