Arch Linux

_oggy

Member

Registered: 2008-09-29

Posts: 26

Lowering resolution on Dell E6510/Intel GM45HD

Not sure if this is the right forum... anyway, I seem to be unable to lower the resolution on my laptop screen from the default one of 1600x900 (I need to get it to 1024x768 to clone the output to a projector). Attaching an external monitor works fine, and I can choose between a range of resolutions for it. Some output from xrandr:

$ xrandr -q
Screen 0: minimum 320 x 200, current 1600 x 2100, maximum 8192 x 8192
eDP1 connected 1600x900+0+1200 (normal left inverted right x axis y axis) 344mm x 194mm
   1600x900       60.0*+   40.0  
VGA1 connected 1600x1200+0+0 (normal left inverted right x axis y axis) 367mm x 275mm
   1600x1200      60.0*+
   1280x1024      75.0     60.0  
   1152x864       75.0  
   1024x768       75.1     60.0  
   800x600        75.0     60.3  
   640x480        75.0     60.0  
   720x400        70.1  
HDMI1 disconnected (normal left inverted right x axis y axis)
DP1 disconnected (normal left inverted right x axis y axis)
HDMI2 disconnected (normal left inverted right x axis y axis)
HDMI3 disconnected (normal left inverted right x axis y axis)
DP2 disconnected (normal left inverted right x axis y axis)
DP3 disconnected (normal left inverted right x axis y axis)

As per Arch Wiki, I tried manually creating and adding the folowing mode:

$ cvt 1024 768 60 -r
# 1024x768 59.87 Hz (CVT 0.79M3-R) hsync: 47.30 kHz; pclk: 56.00 MHz
Modeline "1024x768R"   56.00  1024 1072 1104 1184  768 771 775 790 +hsync -vsync

However, if I try to set eDP1 to this mode, the screen just goes black. Switching to a console terminal works, and
I can kill the X server by a keyboard shortcut. However, the screen remains black even if I try to switch back to
the "default" mode by a shell script:

#!/bin/bash
xrandr --output eDP1 --mode 1024x768R
sleep 2
xrandr --output eDP1 --mode 1600x900

Any ideas?

Edit: forgot to repeat the info from the subject line: I'm running a Dell Latitude E6510 laptop, with integrated Intel GM45HD video.

Last edited by _oggy (2012-02-28 11:36:49)