Requested size (2944, 1080) exceeds 3D hardware limit

[Agoston Sasvari]

IBM T60 laptop (1024x768), and an external monitor, Benq E2200HDA (1920x1080) connected.

Displays with expected resolutions only if one above/below the other, not left or right.

Xrandr say:
Screen 0: minimum 8 x 8, current 1920 x 1848, maximum 32767 x 32767
LVDS1 connected primary 1024x768+0+0 (normal left inverted right x axis y axis) 286mm x 214mm
   1024x768 60.00*+ 50.00
   800x600 60.32 56.25
   640x480 60.00 59.94
   512x384 60.00
DVI1 disconnected (normal left inverted right x axis y axis)
VGA1 connected 1920x1080+0+768 (normal left inverted right x axis y axis) 476mm x 268mm
   1920x1080 59.96*+
   1680x1050 59.95
   1280x1024 75.02 60.02
   1440x900 74.98 59.89
   1280x960 60.00
   1280x800 59.81
   1152x864 75.00
   1152x720 59.97
   1024x768 75.08 60.00
   832x624 74.55
   800x600 75.00 60.32
   640x480 75.00 60.00
   720x400 70.08
   1920x1080_60.00 59.96
VIRTUAL1 disconnected (normal left inverted right x axis y axis)

Forcing fitting any screen left/right of the other results in black screen with xrandr.

Trying to fit them left/right with System Settings > Screen Display says:
 GDBus.Error:org.gtk.GDBus.UnmappedGError.Quark._gsd_2drr_2derror_2dquark.Code3: Requested size (2944, 1080) exceeds 3D hardware limit (2048, 2048). You must either rearrange the displays so that they fit within a (2048, 2048) square.

System:
- Ubuntu 16.04.2 LTS
- expected to happen: built up screen and VGA1 fits left/right as it works with XP.
- what happenes: see above.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: xserver-xorg 1:7.7+13ubuntu3
ProcVersionSignature: Ubuntu 4.4.0-78.99-generic 4.4.62
Uname: Linux 4.4.0-78-generic i686
.tmp.unity_support_test.0:

ApportVersion: 2.20.1-0ubuntu2.6
Architecture: i386
CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CompositorRunning: compiz
CompositorUnredirectDriverBlacklist: '(nouveau|Intel).*Mesa 8.0'
CompositorUnredirectFSW: true
CurrentDesktop: Unity
Date: Mon May 29 12:06:57 2017
DistUpgraded: Fresh install
DistroCodename: xenial
DistroVariant: ubuntu
ExtraDebuggingInterest: Yes, if not too technical
GraphicsCard:
 Intel Corporation Mobile 945GM/GMS, 943/940GML Express Integrated Graphics Controller [8086:27a2] (rev 03) (prog-if 00 [VGA controller])
   Subsystem: Lenovo ThinkPad R60/T60/X60 series [17aa:201a]
   Subsystem: Lenovo ThinkPad R60/T60/X60 series [17aa:201a]
InstallationDate: Installed on 2017-05-23 (5 days ago)
InstallationMedia: Ubuntu 16.04 LTS "Xenial Xerus" - Release i386 (20160420.1)
MachineType: LENOVO 19524TC
PccardctlIdent:
 Socket 0:
   no product info available
PccardctlStatus:
 Socket 0:
   no card
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.4.0-78-generic root=UUID=f2865c0e-961d-4c45-8734-4152a94446fa ro quiet splash vt.handoff=7
SourcePackage: xorg
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 03/21/2011
dmi.bios.vendor: LENOVO
dmi.bios.version: 79ETE7WW (2.27 )
dmi.board.name: 19524TC
dmi.board.vendor: LENOVO
dmi.board.version: Not Available
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Not Available
dmi.modalias: dmi:bvnLENOVO:bvr79ETE7WW(2.27):bd03/21/2011:svnLENOVO:pn19524TC:pvrThinkPadT60:rvnLENOVO:rn19524TC:rvrNotAvailable:cvnLENOVO:ct10:cvrNotAvailable:
dmi.product.name: 19524TC
dmi.product.version: ThinkPad T60
dmi.sys.vendor: LENOVO
version.compiz: compiz 1:0.9.12.2+16.04.20160823-0ubuntu1
version.libdrm2: libdrm2 2.4.70-1~ubuntu16.04.1
version.libgl1-mesa-dri: libgl1-mesa-dri 12.0.6-0ubuntu0.16.04.1
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 12.0.6-0ubuntu0.16.04.1
version.xserver-xorg-core: xserver-xorg-core 2:1.18.4-0ubuntu0.2
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 2:2.99.917+git20160325-1ubuntu1.2
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.12-1build2
xserver.bootTime: Mon May 29 11:24:21 2017
xserver.configfile: default
xserver.errors:

xserver.logfile: /var/log/Xorg.0.log
xserver.outputs:
 product id 16416
 vendor LEN
xserver.version: 2:1.18.4-0ubuntu0.2

[Paul White (paulw2u)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. We are sorry that we do not always have the capacity to review all reported bugs in a timely manner.

Ubuntu 16.04 (xenial) reached end-of-standard-support on April 29, 2021.

I'm setting the status of this bug to 'Incomplete' as it's not seen any activity for some time. If this is still an issue when using a currently maintained release of Ubuntu then please let us know which one(s) otherwise this bug report can be left to expire in approximately 60 days time.

[Launchpad Janitor (janitor)]

[Expired for xorg (Ubuntu) because there has been no activity for 60 days.]