Unable to achieve greater resolution than 800x600

Solution Verified - Updated -

Environment

  • Red Hat Enterprise Linux 6
  • Red Hat Enterprise Linux 5

Issue

  • Some systems report through the System, Preferences, Display tool that they are incapable of resolutions higher than 800x600 when they are actually capable of greater resolutions than that. This will cause a failure of the VIDEO section of the hardware certification tests as it requires 1024x768 @ 24 bpp as a minimum resolution / color depth.

Resolution

There are several things that can be tried to work around this problem:

  • Add the parameter "resolution=1024x768" to the kernel line in grub.conf.
  • Add the parameter "video=1024x768" to the kernel line in grub.conf.
  • Modify and use the following xorg.conf file to allow your system to achieve the 1024x768 resolution necessary for hardware certification. To create an xorg.conf, refer How to create "xorg.conf" to configure X Windows on a system with no prior X configuration ?
    # This xorg.conf file has been designed for systems that support a resolution
    # of 1024x768 or greater, but only lower resolutions are listed in the
    # computer's System, Preferences, Display application. It assumes that X works
    # at low resolutions. It will allow you to achieve the 1024x768 resolution 
    # necessary for hardware certification purposes if you save it as xorg.conf,
    # place it in the /etc/X11 directory and restart X. Please read the other 
    # comment lines in this file and follow their directions to prepare the 
    # file for use. 
    
    Section "Monitor"
         Identifier   "Monitor0"
         ModelName    "LCD Panel 1024x768"
    # The HorizSync and VertRefresh lines below are designed for a generic LCD
    # monitor. They should also work for modern CRT monitors. If you know your 
    # monitor's values, replace the ones shown below with those values. 
    # Otherwise, uncomment the next two lines and use them as-is.
    #     HorizSync    31.5 - 48.0
    #     VertRefresh  56.0 - 65.0
         Option         "dpms"
    EndSection
    
    Section "Device"
         Identifier  "Videocard0"
    # The Driver line below should contain the appropriate driver for your system.
    # You can find your driver by looking at the system's /var/log/Xorg.0.log file
    # for lines that begin with driver names, like these:
    #
    # This is an example of a system using the Matrox 'mga' driver
    # (II) MGA(0): initializing int10
    # (II) MGA(0): Primary V_BIOS segment is: 0xc000
    # (II) MGA(0): VESA BIOS detected
    # (II) MGA(0): VESA VBE Version 3.0
    #
    # This is an example of a system using the Aspeed 'ast' driver
    # (II) AST(0): initializing int10
    # (II) AST(0): Primary V_BIOS segment is: 0xc000
    # (II) AST(0): VESA BIOS detected
    # (II) AST(0): VESA VBE Version 3.0
    # 
    # Replace the 'vesa' on the Driver line below (unless you are using the vesa 
    # driver) with the proper driver for your system and then uncomment the line.
    #     Driver      "vesa"
    EndSection
    
    Section "Screen"
         Identifier "Screen0"
         Device     "Videocard0"
         Monitor    "Monitor0"
         DefaultDepth     24
         SubSection "Display"
              Viewport   0 0
              Depth     24
         EndSubSection
    EndSection
    

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