CentOS - Jun 2006 - How do you set the refresh frequency for the X server?

During the kickstart installation of the CentOS 4.3 systems I  
recently built, anaconda probed for the video card (Intel 945) and  
monitor (NEC MultiSync 2070NX).  The optimal setting for this monitor  
is 1600x1200 @ 60Hz.  The X server is configured to use 1600x1200,  
but it is using a higher refresh rate, which causes the monitor to  
display an error message, and it also locks you out of the on-screen- 
menu.  How do you translate a 60Hz refresh frequency into the  
appropriate horizontal sync and vertical refresh frequencies in the  
xorg.conf file?  I can't find anything to change in system-config- 
display.  Any suggestions?

Thanks,
Alfred

On Mon, 2006-06-26 at 09:55 -0400, Alfred von Campe
wrote:
> During the kickstart installation of the CentOS 4.3 systems I  
> recently built, anaconda probed for the video card (Intel 945) and  
> monitor (NEC MultiSync 2070NX).  The optimal setting for this monitor  
> is 1600x1200 @ 60Hz.  The X server is configured to use 1600x1200,  
> but it is using a higher refresh rate, which causes the monitor to  
> display an error message, and it also locks you out of the on-screen- 
> menu.  How do you translate a 60Hz refresh frequency into the  
> appropriate horizontal sync and vertical refresh frequencies in the  
> xorg.conf file?  I can't find anything to change in system-config- 
> display.  Any suggestions?
Here is some information I have used as background.

    http://linuxconsole.sourceforge.net/fbdev/HOWTO/3.html

The above seems thorough, but is murky in some ways - refs to apply the
previous formula when there are more than one. I also seem to recall
that Brian J. Smith had posted something on this. Maybe searching the
archives? I hope my memory's not wrong, searches can *eat* time. He also
has a blog and it would be referenced in archives too I think.

I seem to remember that there was a post of a very easy formula posted
in the LinuxFromScratch archives long ago. Googling there with 

   site:linuxfromscratch.org

as one of the args might find that as well.
> 
> Thanks,
> Alfred
> <snip sig stuff>
HTH
-- 
Bill
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Bill:
> Here is some information I have used as background.
>
>     http://linuxconsole.sourceforge.net/fbdev/HOWTO/3.html
Thanks, there is some interesting information there.  I did some more  
googling since my previous post, and I found some examples on how to  
*increase* the refresh frequency.  However, in my case I want to set  
the refresh frequency to exactly 60 Hz.  I think I also found that  
the refresh frequency (usually what you configure in Windows, i.e.,  
1024x768 at 75Hz) corresponds to the VertRefresh entry in the xorg.conf  
file.  However, when I set that to 60 (instead of the monitor's 56.0  
- 85.0 range), the problem didn't go away.  I probably also have to  
adjust the HorizSync entry, but I don't know to what exactly.

Alfred