[Sussex] Resolutions

[Gavin Stevens]

On Fri, 12 Aug 2005 10:56:08 +0100
Ronan Chilvers <ronan at thelittledot.com> wrote:

> Hi folks
> 
> Can anyone shed some light on an annoying X resolution problem?  I'm
> using a flat screen monitor at work (HP 1702 TFT) which is capable of
> 1280x1024.  The machine used to have Mandrake 10 on it which happily
> drove the monitor at the right resolution.  However since installing
> Ubuntu, I can't get the resolution higher than 1024x768 without it
> using a virtual desktop space (ie: the desktop extends out beyond the
> monitor ), as if the highest resolution was 1024x768.  I've tried
> generating some Modelines for the full resolution, using the monitor
> specs from the HP site with no joy - same thing happens.  I know it
> will do the full resolution because it has quite happily in the past.
> 
> Unfortunately I don't know the Mandrake 10 X server version which
> might have helped, but the current one is the standard Ubuntu Hoary
> xorg version 6.8.2. The graphics card is an on-board Intel 82865G PCI
> device using the native X driver's built resolutions / modes which
> does list 1280x1024 as supported in Xorg.0.log.  However the log also
> contains the line
> 
> (II) I810(0): Not using built-in mode "1280x1024" (width too large for
> virtual size)
> 
> Any ideas anyone?  If you need to know anything else let me know. I
> can attach over xorg.conf files, etc as required.
> 
> Cheers
> 
> Ronan
> 
Hi Ronan,

I use Ubuntu at present on my main PC (P4 2.8GHz, 512MB RAM) & Gnome
happily runs my preferred resolution.

I also have a P3 850 that I built for trying things out. I installed
Debian Sarge on this & allowed tasksel to install a "Desktop
Environment", which runs the same Gnome as Ubuntu.

Both of these PCs share the same (CRT) monitor via a KVM switch. The
850MHz PC running Debian would not allow a resolution higher than
800x600 in Gnome.

I re-installed Debian Sarge on the 850 machine & this time installed
basic X & IceWm manually & it now runs at 1024x768, which is my
preferred resolution.

Based on this, it seems that Gnome somehow downgrades the resolution on
lower spec machines so that it can run at a reasonable speed. I could be
wrong in this theory, but that's how it seems to me.

So if your PC is an older machine, then my theory might be true, but if
you've got an up-to-date P4 type PC, then my hypothesis is in tatters.

Gavin.