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dkinfl 10-23-2007 08:21 AM

Monitor change
I have red hat loaded on a dell GX270, BIOS A07, intel video card 865. I had a 15"lcd on it, and it was working fine. Now, I have purchased and hooked up a dell 22" wide screen LCD. It has a native res of 1680 x 1050. However, linux still shows the old monitor in the xorg.conf, and will not go any higher than 1280x960 resolution, despite my efforts to edit the xorg.conf manually. Anyone have any suggestions?

pixellany 10-23-2007 08:36 AM

For my Dell 24", I had to set up a modeline. I got this by using the "gtf" utility.

LCDs like to be run at their native resolution, and at 60Hz vertical refresh. I did this by using VertRefresh 59.9-60.1 (This acutally might be redundant, since a modeline sets the pixel clock directly.)

I don't know if it matters, but GTF set the sync polarities different from what the Dell manual specifies--I just changed them by hand

dkinfl 10-23-2007 08:58 AM

I ran the gtf and it produced the modeline output. Does this need to be added to the xorg.conf?

pixellany 10-23-2007 03:19 PM

Here is a relevant excerpt from my xorg.conf:


Section "Monitor"
Identifier "monitor1"
VendorName "Generic"
ModelName "Flat Panel 1920x1200"
Option "DPMS"
HorizSync 31.5-90
VertRefresh 59.9 - 60.1
Modeline "1920x1200" 193.16 1920 2048 2256 2592 1200 1201 1204 1242
+Hsync -Vsync

Section "Device"
Identifier "device1"
VendorName "nVidia Corp."
BoardName "NVIDIA GeForce FX (generic)"
Driver "nv"

Section "Screen"
Identifier "screen1"
Device "device1"
Monitor "monitor1"
DefaultColorDepth 24

Subsection "Display"
Depth 24
Modes "1920x1200" "1440x900" "1280x800"
Obviously, your modeline will be different, your card maybe different, etc. (I think) you only need the highest res mode named in Subsection "Display". I'm still experimenting and learning.

Note the polarity of Hsync and Vsync. gtf produced the opposite, and I changed it to match what my manual says.

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