[CentOS] Problem with widescreen display

[B.J. McClure]

On Mon, 2008-11-03 at 10:56 +0100, Rainer Duffner wrote:
> Marko Vojinovic schrieb:
> > On Sunday 02 November 2008 12:26, William L. Maltby wrote:
> >   
> >> On Sat, 2008-11-01 at 22:08 +0000, Marko Vojinovic wrote:
> >>     
> >>> Basically, what I did was to run system-config-display to reconfigure for
> >>> the new monitor and resolution. All goes well, but after X restarts, I
> >>> see a strange picture: the resolution indeed goes to 1680x1050 as is
> >>> supposed to, but is squeezed/shrinked/scaled horizontally to match a 4:3
> >>> aspect ratio, leaving two (unequal) black bands on the left and right
> >>> side of the monitor.
> >>>       
> >> This sounds like the "Modes" line in the "Subsection Display" may not
> >> have the right settings. The manual/CD for the monitor should have the
> >> right settings. I would compare those against what the configuration
> >> process generated and manually edit if needed. Why the difference
> >> between FC4 and CentOS, I can't guess.
> >>     
> >
> > Comparing the CentOS and Fedora Xorg.0.log I found that the actual modelines 
> > are just slightly different. Assuming that this difference might actually be 
> > important, I took the known-to-work modeline from Fedora's Xorg.0.log, 
> > copy-paste it in CentOS xorg.conf and forcing X to use that. But the result 
> > is the same.
> >   
> 
> I only run CentOS on servers, but when I got my widescreen monitor at
> work, I couldn't get the full resolution with the X that came with
> OpenSuSE 10.3.
> Only OpenSuSE 11 works.
> Too bad that printing doesn't work in OpenSuSE 11 anymore....
> My take: the X-server makes some assumptions that are not true for
> widescreen hardware and throws away the modelines it gets (because it
> thinks they won't work). Seems to have been fixed with later X releases
> (or patches).
> For desktop-use, there's little alternative to Ubuntu/OpenSuSE/Fedora
> and re-installing every couple of months (and living with new and
> surprising bugs every release).
FWIW, here is a section from /etc/X11/xorg.cong on a working 22 inch widescreen workstation running 1680x1050.  
We have around 20 machines, all workstations, some 32 bit some 64 bit, all running CentOS 5.2 on Asus hardware 
with various flavors of Nvidia graphics adapters, and all are 22 inch widescreen Viewsonic monitors.

Section "Monitor"
    Identifier     "Monitor0"
    VendorName     "Unknown"
    ModelName      "Unknown"
    HorizSync       30.0 - 110.0
    VertRefresh     50.0 - 150.0
    Option         "DPMS"
EndSection

Section "Device"
    Identifier     "Videocard0"
    Driver         "nvidia"
With all due respect, to suggest that CentOS is unsat for desktop use is simply incorrect. All 
servers(no GUI) and workstations we have run CentOS.  Only for laptops do we consider Ubuntu LTS.

Cheers,
B.J.

CentOS 5.2, Linux 2.6.18-92.1.13.el5 x86_64 04:11:11 up 6 days, 12:58, 1
user, load average: 0.03, 0.06, 0.08