ATI Dual Monitor Xinerama with different resolutions

Hallo Forum!

First my system data:

  • OpenSuse 11.4 x64
  • KDE SC 4.6.2
  • ATI HD 5800
  • Catalyst 11.2 (flgrx 8.821)
    1. monitor LG LX20D (1600x1200)
    1. monitor LG IPS236V (1920x1080)

Today I bought a new monitor (IPS236V) to use it to watch movies and tv while I’m working on the other one… I thought it’s the best to activate Xinerama which could be done easy via CCC. But I’m not able to change the resolutions now as these panels are disabled in CCC. The first monitor is set to its native resolution, but the second is something lower.
How can I configure both monitors to there native resolution?

Thanks in advance

It is tricky. You’ll probably have to edit /etc/X11/xorg.conf … and it should look (more or less!) like this:

# **********************************************************************
# Server flags section.
# **********************************************************************
Section "ServerFlags"
	Option	    "Xinerama" "0"
	Option	    "ZapWarning" "off"
EndSection


# **********************************************************************
# Monitor section
# **********************************************************************
Section "Monitor"
	Identifier  "0-DFP2"
	Option	    "VendorName" "LG"
	Option	    "ModelName" "LG LX20D"
	Option	    "DPMS" "true"
	Option	    "PreferredMode" "1600x1200"
	Option	    "TargetRefresh" "60"
	Option	    "Position" "0 0"
	Option	    "Rotate" "normal"
	Option	    "LeftOf" "0-CRT1"
	Option	    "Disable" "false"
EndSection

Section "Monitor"
	Identifier  "0-CRT1"
	Option	    "VendorName" "LG"
	Option	    "ModelName" "LG IPS236V"
	Option	    "DPMS" "true"
	Option	    "PreferredMode" "1920x1080"
#	Option	    "RighttOf" "0-DFP2"
	Option	    "TargetRefresh" "60"
	Option	    "Position" "1600 0"
#	Option	    "Rotate" "left"
	Option	    "Enable" "true"
	Option	    "Rotate" "normal"
	Option	    "Disable" "false"
EndSection

# **********************************************************************
# Graphic cards section
# **********************************************************************
Section "Device"
	Identifier  "Radeon HD5800"
	VendorName  "ATI Technologies Inc"
	BoardName   "Radeon HD 5800"
#	BusID       "PCI:1:5:0"
	Driver      "fglrx"
	Option	    "DRI"
	Option	    "Monitor-CRT1" "0-CRT1"
	Option	    "Monitor-DFP2" "0-DFP2"
EndSection

# **********************************************************************
# Screen section
# **********************************************************************

Section "Screen"
	Identifier "Screen0"
	Device     "Radeon HD5800"
	DefaultDepth     24
 	Monitor    "0-CRT1"
	Monitor    "0-DFP2"
 	Option	    "Monitor-CRT1" "0-CRT1"
 	Option	    "Monitor-DFP2" "0-DFP2"
	SubSection "Display"
 		Viewport  0  0
		Virtual   3520 3520
		Depth     24
		Modes    "1600x1200"
	EndSubSection
EndSection

Section "Extensions"
	Option	    "Composite" "Enable"
EndSection

# **********************************************************************
# ServerLayout sections.
# **********************************************************************

Section "ServerLayout"
	Identifier     "Dual"
	Screen      0  "Screen0" 0 0
	Option	    "Xinerama" "off"
	Option	    "Clone" "off"
EndSection

I’ve tried to edit it for you. I doubt it’s going to work without some changes. But it’s a good start. Use the command lspci to find out the BUS ID of your graphic card. It’s commented out in this example. We don’t use Xinerama anymore.

Thanks for your reply!

This setting workes for me. Although I found out that the ATI CCC configures xorg.conf this way by choosing the right options: In the section ‘Display-manager’ is a tab ‘Multiple displays’ where I can choose the big desktop option.
Now it workes the way I want it.

Yes, That’s the way to do it with CCC. However it used to use xinerama. The result was pretty much looking the same, but it was much slower and less stable (also used much more resources to move windows between monitors). I don’t know if it is still the case. To find out if CCC and my hand written configuration does the same, you’ll have to compare the manually edited and CCC generated xorg.conf.
Anyway, I’m glad it solved your problem - and kind of surprised that it worked right away.

Well done with your good support here please_try_again! (I’ve clicked the ‘Reputation’ button for you). I have a personal laptop with a X300 chipset (using the radeon driver), so was reluctant to assist directly. Although I’m familiar with the amdcccle utility, I wasn’t sure about the Xinerama or XRandR status with the fglrx driver, but this contemporary info may assist others using the proprietary AMD/ATI driver.

To find out if CCC and my hand written configuration does the same, you’ll have to compare the manually edited and CCC generated xorg.conf.

That would be interesting.

please_try_again, well done ! I’m impressed you were able to propose an example xorg.conf with the information provided. You had to make some assumptions and it appears you were right on the money with those that you made. Most impressive !