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I'm trying to adjust resolution on my new MSI GT70 2OC. In settings, only one resolution is available: 1920x1080. This is fine, except that I need to decrease the resolution and make it more rectangular for the laptop to work well with my old PL-550 tablet.

Here's what I do:

cvt 1200 1000 60
    # 1200x1000 59.91 Hz (CVT) hsync: 62.19 kHz; pclk: 99.50 MHz
    Modeline "1200x1000_60.00"   99.50  1200 1280 1400 1600  1000 1003 1013 1038 -hsync +vsync
sudo xrandr --newmode "1200_1000_60"   99.50  1200 1280 1400 1600  1000 1003 1013 1038 -hsync +vsync
    xrandr: Failed to get size of gamma for output default

How do I get past this step?

UPDATE Here's the output of xrandr:

xrandr: Failed to get size of gamma for output default
Screen 0: minimum 1920 x 1080, current 1920 x 1080, maximum 1920 x 1080
default connected primary 1920x1080+0+0 0mm x 0mm
   1920x1080       0.0* 
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up vote 3 down vote accepted

You don't need sudo to register the new mode with xrandr, try without sudo. Then you'll have to apply the new resolution with:

xrandr --addmode <your_connection_type> 1200x1000_60.00

Where <your_connection_type> is usually VGA1, DP1 or HDMI1. Check the output of xrandr to know the exact name of the connected output.

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see update..... – Arsen Zahray Mar 30 '14 at 12:45
I'm pretty sure that this msg (the gamma size) is harmless, did you try to apply the new mode with xrandr --addmode? – Sylvain Pineau Mar 30 '14 at 12:48
yes, you were absolutely right! But, now I'm getting another message. 1200x1000 doesn't fit between 1920x1080 and 1920x1080. Any idea what I can do about that? – Arsen Zahray Mar 30 '14 at 13:57
I'm getting that message when I'm trying to change the resolution to 1200x1000 in the settings – Arsen Zahray Mar 30 '14 at 14:04

If you have an nVidia or ATI GPU, have you tried changing your driver, either from proprietary to non-proprietary or vice versa?

My system:

~$ inxi -G
Graphics:  Card: NVIDIA C61 [GeForce 7025 / nForce 630a] 
           X.Org: 1.15.1 drivers: nouveau (unloaded: fbdev,vesa) Resolution: 1920x1080@60.0hz 
           GLX Renderer: Gallium 0.4 on NV4C GLX Version: 2.1 Mesa 10.1.3

Depending on what kernel/distribution I am running, sometimes the proprietary nVidia 304 driver works, on others, e.g. Bodhi 3.0, with the same setup, can fail to read properly the size of the screen and also fail to read the gamma.

You can try to set your output with the following line, which will at least fix your error report, but may not fix your output:

xrandr --output default --gamma 0:0:0 --mode 1200x1000

You may also want to install the inxi utility and post the output of inxi -G here for more help.

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I had this problem too, but after installing the proper nvidia driver, all my problems were fixed.

Follow this guide to install the nvidia driver

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