Bug 704764

Summary:	Gnome shell really slow after attaching a second monitor
Product:	[Fedora] Fedora	Reporter:	HulkDerHungrige
Component:	gnome-shell	Assignee:	Owen Taylor <otaylor>
Status:	CLOSED NOTABUG	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	15	CC:	maxamillion, otaylor, samkraju, tomek, walters
Target Milestone:	---
Target Release:	---
Hardware:	i386
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2011-05-23 10:08:35 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description HulkDerHungrige 2011-05-14 19:21:12 UTC

Description of problem:
After attaching a second monitor to my notebook the desktop it successfully extended but the gnome shell behaves very slow and is actually unusable because a mouseclick is processed after more than ten seconds. /usr/bin/top shows that gnome-shell uses more than 50% of cpu (normally 1%). After disconnecting the second monitor, gnome-shell behaves well.

Version-Release number of selected component (if applicable):
gnome-shell-3.0.1-4.fc15.i686
xorg-x11-drv-intel-2.15.0-3.fc15.i686

How reproducible:
Just attach a second monitor to your Fedora 15 notebook and try it.
 
Expected results:
The desktop should be usable with the second monitor.

Comment 1 Tomasz Torcz 2011-05-23 09:46:40 UTC

Are you by chance running on i945 hardware? If so, attaching second monitor could make your desktop extend beyond 2048 pixels and run into hardware limits.
If you have i945 hardware, I suggest stacking your monitor vertically (to be within 2048 limit).
You can also try to boot with second monitor attached. You should be taken straight into Fallback mode.