Take the 2-minute tour ×
Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

I need to have my VNC viewer session to a Linux PC display a larger screen.

On the Linux PC I am VNC'd into, the command xrandr -q shows only 4 modes available, the largest being 1024x768.

Comparing to another Linux PC which displays the size I want, the same command xrandr -q shows it is at mode 1200x1024.

Both the Windows PC I am on and the 2 Linux PC's I VNC into are running RealVNC free edition.

How to I get the 1200x1024 mode to be available via VNC?

share|improve this question
    
Is VNC really the issue, or does xrandr report the same resolution when logged in locally on the Linux PC? –  Nate from Kalamazoo Jun 26 '13 at 12:24
add comment

1 Answer

If you are sure that your video setup on that Linux PC supports a higher resolution such as 1200x1024, you could use xrandr's newmode to manually add that resolution as described here: https://wiki.archlinux.org/index.php/Xrandr#Adding_undetected_resolutions

First determine the modeline using cvt

$ cvt 1200 1024
# 1200x1024 59.82 Hz (CVT) hsync: 63.59 kHz; pclk: 101.75 MHz
Modeline "1200x1024_60.00"  101.75  1200 1280 1400 1600  1024 1027 1037 1063 -hsync +vsync

Create a new mode in xrandr based on that output:

xrandr --newmode "1200x1024_60.00"  101.75  1200 1280 1400 1600  1024 1027 1037 1063 -hsync +vsync

Add that new mode to your current output:

 xrandr --addmode VGA1 1200x1024_60.00

Then switch to the new resolution:

xrandr --output VGA1 --mode 1200x1024_60.00

The authors of that wiki smartly suggest adding an automatic fallback mode following a five second delay, in case the new resolution totally borks your setup:

xrandr --output VGA1 --mode 1200x1024_60.00 && sleep 5 && xrandr --newmode "1024x768-safe" 65.00 1024 1048 1184 1344 768 771 777 806 -HSync -VSync && xrandr --addmode VGA1 1024x768-safe && xrandr --output VGA1 --mode 1024x768-safe
share|improve this answer
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.