Red Hat Bugzilla – Bug 124267
Incorrectly uses Clone definitions to override Primary
Last modified: 2007-11-30 17:10:43 EST
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User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0)
Description of problem:
If, as I do, you have a graphics card capable of multihead, you can
get a situation where the best resolution if 640x480. This is forced
upon the normal (higher) resolution by having a virtual "window" onto
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1.Plug in the "wrong" monitor with a multihead capable graphics card
2.Use X (either Gnome or KDE)
Actual Results: A 640x480 "window" onto a 1028x768 desktop (or gdm)
Expected Results: A 1028x768 desktop filling my screen. Please note
that I do not and never have had a second monitor.
Full description here :-
Add these lines to the Device section of /etc/X11/XF86Config
Option "CloneHSync" "30.0-72.0"
Option "CloneVRefresh" "50.0-160.0"
(the numbers - 30.0-72.0 and 50.0-160.0 - dependant upon monitor
And add a dummy screen and monitor section to the same config file.
This FIX / Work around works for Fedora Core 1 and Core 2, Mandrake
10.0 Community (was not needed for Mandrake 9.2 or Slackware 9.1,
which I have on the same PC).
Is this a bug or a feature that needs better documentation ?
If you change monitors, you need to reconfigure the X server, or
it will not work correctly depending on the particulars of the
monitors and various other factors. This issue may not occur
in the same way on Mandrake or other distributions perhaps due
to different configuration files settings between the distributions.
The Radeon driver in each of the 3 distributions is also quite
different. The Clone settings you indicate may work around your
particular problem for your case, but they are not settings which
should be applied to all Radeon hardware for all users. If you
rerun the config tool: "system-config-display --reconfig" it will
generate a new config file, which will handle your new monitor.
Assuming your new monitor can be correctly DDC probed, it should
just work without any further configuration. If the problem recurs
however, please attach your complete X server log and config file
from the problematic run for analasis.
Thanks for the report.
Since this bugzilla report was filed, there have been several major
updates to the X Window System, which may resolve this issue. Users
who have experienced this problem are encouraged to upgrade to the
latest version of Fedora Core 3, which can be obtained from:
If this issue turns out to still be reproduceable in the latest
version of Fedora Core, please file a bug report in the X.Org
bugzilla located at http://bugs.freedesktop.org in the "xorg"
Once you've filed your bug report to X.Org, if you paste the new
bug URL here, Red Hat will continue to track the issue in the
centralized X.Org bug tracker, and will review any bug fixes that
become available for consideration in future updates.