radeon, M22 X300, a pair of monitors, and maximizing resolution with good performance

[Thomas Vaughan]

I sent the following message originally to the Debian maintainer of
the xserver-xorg-video-ati package.  He recommended that I send my
question to this list.

---------- Forwarded message ----------
From: Thomas Vaughan <tevaughan at gmail.com>
Date: Thu, Mar 27, 2008 at 1:57 PM
Subject: radeon, M22 X300, a pair of monitors, and maximizing
resolution with good performance
To: bgoglin at debian.org


Hello, I saw your e-mail address on the changelog for
 xserver-xorg-video-ati.

 Please disregard this message if you are too busy to read it.  :^)

 What I'd like to do is to maximize the resolution of my dual-monitor
 setup when my laptop is docked.  I have a pair of 1600x1200 monitors,
 and, according to lspci, my laptop has an ATI Technologies Inc M22
 [Mobility Radeon X300].  And I run Debian unstable.

 Anyway, it seems that if I want to do OpenGL stuff, such as to run a
 screensaver, then I really need to keep my total horizontal resolution
 under 2560 pixels.  The screen saver puts garbage onto the right side of
 the display for columns greater than about 2560.  What I'm doing to work
 around the problem is to use a virtual desktop size of 2560x1024.  This
 is suboptimal because of the blurry effect of not using a resolution
 that matches the LCD panel's native resolution.

 So I thought that I might just rotate my two monitors and make a virtual
 desktop of 2400x1600.  The problem that I encountered, however, was of
 painfully slow performance, even for ordinary 2D operations, like
 moving a window.  Is there any way of setting up a pair of monitors in
 portrait mode with decent 2D and 3D acceleration, or is this just not
 supported?

 Unfortunately, mechanically putting my monitors one over the other,
 for a virtual size of 1600x2400, would require pieces of metal and a
 truss that I don't have. :^(

-- 
Thomas E. Vaughan