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Can't get T43 LCD to display at 60Hz in Linux. [SOLVED]

Posted: Tue Mar 06, 2007 11:44 pm
by dhave
I've got a T43 with ATI X300 64Mb graphics. When I run Windows, the default resolution is 1400x1050@60Hz. When I run Linux (Gentoo), the reported resolution is 1400x1050@50Hz.

I'm pretty accustomed to fiddling with my xorg.conf file for monitor and other adjustments, but nothing I do seems to override what I take to be a private conversation between the display device and the LCD screen. The "IgnoreEDID" setting doesn't do anything, nor do my attempts to set a custom vertical refresh rate.

Any help would be appreciated.

Posted: Wed Mar 07, 2007 12:26 am
by dhave
FWIW, here's the output of "xrandr -q" on my system:

Code: Select all

 SZ:    Pixels          Physical       Refresh
*0   1400 x 1050   ( 404mm x 303mm )  *50  
 1   1280 x 1024   ( 404mm x 303mm )   50  
 2   1152 x 864    ( 404mm x 303mm )   50  
 3   1024 x 768    ( 404mm x 303mm )   50  
 4    800 x 600    ( 404mm x 303mm )   50  
 5    640 x 480    ( 404mm x 303mm )   50  
 6    640 x 400    ( 404mm x 303mm )   50  
 7    640 x 350    ( 404mm x 303mm )   50  
 8    512 x 384    ( 404mm x 303mm )   50  
 9    400 x 300    ( 404mm x 303mm )   50  
 10   320 x 240    ( 404mm x 303mm )   50  
 11   320 x 200    ( 404mm x 303mm )   50  
Current rotation - normal
Current reflection - none
Rotations possible - normal 
Reflections possible - none
I'm wondering why the default refresh rate isn't 60.

Also, when I do "xrandr -r 60" I get this: "Rate 60 is not available for this size."

When I do "xrandr -r 50", the system accepts it.

Posted: Wed Mar 07, 2007 9:27 am
by richp
While other than selling and using them, LCD's, I was unaware that referesh rates were anything more than a hold over from CRT's. Those I could see. Do refresh rates actually do anything with an LCD ?

Posted: Wed Mar 07, 2007 10:06 am
by Leikeze Ajnin
The refresh rate mostly applies to CRT monitors; specifically the functioning of the electron beam used to colorize the screen. Check out http://en.wikipedia.org/wiki/Refresh_rate for some more of the details.

Posted: Wed Mar 07, 2007 11:54 am
by dhave
I'm learning something here. I'll quick being anxious about my LCD screen's refresh rate and find something else to worry about.

Thanks.