Setting Specific Scan Rate in xorg.conf: Puzzled

Ari Torhamo ari.torhamo at
Tue Apr 4 01:13:52 UTC 2006

ma, 2006-04-03 kello 18:41 -0400, Kent Borg kirjoitti:
> I have a new LCD panel and I can't get a stable display on it--text
> and vertical lines flutter.  Various playing with "dpkg-reconfigure
> xserver-xorg" and pressing the "Auto" button doesn't seem to have
> fixed it, but one thing does have me really puzzled: Why can't I set
> the horizontal and vertical scan rates by editing /etc/X11/xorg.conf
> and changing "HorizSync" and "VertRefresh"?
> One of the "factory presets" listed in the manual is 63.89kHz and 60
> Hz.  I set HorizSync to "63-64" and VertRefresh to "59-61".  This way
> X will have to choose the preset I want right?  Wrong.  When I fire up
> X and ask the monitor what it is being fed it says 74.6 Hz and 79 Khz.
> Why isn't it listening to me?

I found this on
(don't know if it helps at all):
"Since LCD monitors do not employ phosphors, refresh rate is not a
concern. Basically, the transistors in the LCD remain open or closed as
needed until the image changes. This can be a point of confusion for
some consumers, however, since most graphics cards still "ask for" a
refresh rate setting. This is due to the analog nature of existing
graphic cards (see "Inputs" section) and their support for CRT displays.
While refresh rates do not apply to LCD monitors, most LCDs are set up
to accept any settings from 60Hz and above."


More information about the ubuntu-users mailing list