[solved] radeon - How to set up resoluton and frequency?

Ralf Mardorf ralf.mardorf at alice-dsl.net
Tue Oct 16 03:07:10 UTC 2012

Hi :)

I didn't test the /etc/X11/xorg.conf with Precise, but it's ok for
Quantal RC.

Section "ServerLayout"
	Identifier     "X.org Configured"
	Screen      0  "Screen0" 0 0

Section "Monitor"
	Identifier   "Monitor0"
  	DisplaySize  305 230
  	HorizSync    29-98
  	VertRefresh  50-120
	modeline     "1152x864" 128.42 1152 1232 1360 1568 864 865 868 910
  	Gamma	     1.0

Section "Device"
	Identifier  "Card0"
	Driver	"radeon"

Section "Screen"
	Identifier "Screen0"
	Device     "Card0"
	Monitor    "Monitor0"
	SubSection "Display"
		Viewport   0 0
		Depth	24
		Modes      "1152x864"

It's also working with DisplaySize commented out.
It's also working with Gamma commented out.
I tested different Gamma settings and they've got impact.
It's not working, if modeline is commented out.

I'm not sure if the frequencies are always the same, but if they should
differ, than just between HF 81.9 and 82KHz and between VF 89.9 and
90Hz, it's not noticeable. It's not possible to switch between different
frequencies for the wanted 1152x864, but possible to choose lower
resolution. I haven't checked which frequencies are available for lower

3D does work with GoogleEarth.

It might be that in addition it was needed to set up ARandR & Display
settings, but at least there where values to choose, after startup with
this xorg.conf.

Mouse and keyboard settings in xorg.conf didn't brake it, but I don't
know if they have impact. I testet a virtual setting, but it didn't


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