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

Alex Deucher alexdeucher at gmail.com
Fri Mar 28 08:57:59 PDT 2008

On Fri, Mar 28, 2008 at 9:32 AM, Thomas Vaughan <tevaughan at gmail.com> wrote:
> On Fri, Mar 28, 2008 at 2:11 AM, Michel Dänzer
>  <michel at tungstengraphics.com> wrote:
>  >
>  > On Fri, 2008-03-28 at 09:08 +0100, Michel Dänzer wrote:
>  > > On Thu, 2008-03-27 at 21:18 -0600, Thomas Vaughan wrote:
>  > > >
>  > > > So I thought that I might just rotate my two monitors and make a
>  > > > virtual desktop of 2400x1600.
>  Just to be clear---in case anyone might be confused by my sloppy
>  wording---I rotated clockwise each of the two 1600x1200 LCD panels
>  attached to my docking station.  Then I used 'Option "Rotate" "Left"' on
>  each of them.  With side-by-side monitors, each in portrait orientation
>  (instead of the usual landscape orientation), my virtual desktop size
>  was then 2400x1600.

accelerated rotation uses textures to rotate the desktop, so the max
size would be 2048x2048.

>  Also, for anyone else in this conversation, I don't belong to the list.
>  > > > 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?
>  > >
>  > > I think it should be possible, but you need to make sure to use EXA
>  > > instead of XAA and that you use something close to current upstream
>  > > Git - xserver-xorg-video-ati from experimental may or may not fit
>  > > the bill.
>  Thanks!
>  I'll fetch the relevant debs from experimental with a Web browser.  I'm
>  an old guy who still uses dselect for package stuff, and I can never
>  remember how to use apt (to "pin" or whatever) the right bits from
>  experimental.
>  I suppose that there's an Option to use in xorg.conf to enable EXA
>  instead of XAA.

Option "AccelMethod" "EXA"

>  > On second thought, I'm afraid this won't help as the 3D engine
>  > probably only supports textures up to 2048x2048.
>  Well, that would matter (hopefully) only if I actually wanted to use
>  textures bigger than 2048x2048.  Perhaps it would affect me if I wanted
>  to use a big texture for the whole virtual desktop.

When using accelerated rotation with EXA, textures are used so the
limit applies here.

>  Doesn't compiz do something like that?  Although running compiz would be
>  nice, I just want my screen saver and ordinary OpenGL apps to work
>  without putting garbage onto the screen.
>  Anyway, would it be a huge pain for me to check out the source and build
>  it myself?  I use cvs and subversion a lot at work, but I've never
>  messed with git.  Also, I do embedded programming in C at work.  Is
>  there a huge learning curve in coming up to speed on the source and
>  build system for what Debian calls xserver-xorg-video-ati?  I'm not
>  opposed to playing around with it, but my time is limited enough so that
>  I probably can't afford to climb a huge learning curve.

gIt is pretty easy to pick up.  It's not that hard to install from git
so long as you have the needed build dependencies installed (xorg,
xserver-dev  packages from your distro).


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