[Wylug-help] Strange Xorg - Ubuntu Breezy [Mode Clock]

[Dave Fisher]

On Sun, Jul 17, 2005 at 12:43:49PM +0100, Dave Fisher wrote:
> If I find out anything useful or merely interesting I'll let people
> know.

This error looks a bit serious:

  (1600x1200,Generic Monitor) mode clock 162MHz exceeds DDC maximum 140MHz

I've tried to set the video mode to 
  
  1024x768 @ 60Hz

The resulting xorg.conf file shows the following:

  HorizSync       28-49
  VertRefresh     43-72
  <snip>
  SubSection "Display"
          Depth           24
          Modes           "1024x768"
  EndSubSection

The figures for HorizSync and VertRefresh seem to match the preset display
modes for my monitor:

   http://support.dell.com/support/edocs/monitors/E173FP/English/specs.htm#Preset%20Display%20Modes

But I can't see a specific 'mode clock' setting.

From what I read on the specs page, it looks as though Xorg is either
misreading the Extended Display Identification Data (EDID) data it recieves via
the Display Data Channel (DDC) protocol, or is just ignoring it and making up
its own figure.

Can anyone tell me:
  
  1. What (if any) relationship there might be between the refresh rates /
  resolution and the 'mode clock'

  2. How I could set the mode clock to something less than the maximum, or
  (preferrably) set it to an optimum figure?

Dave