GNOME 3 Fallback Mode

[fkooman at tuxed.net]

On Wed, Apr 27, 2011 at 12:48 PM, Camilo Mesias <camilo at mesias.co.uk> wrote:
> On the other hand it will be awesome when it's finished and possibly
> will remove the need for fallback mode altogether.

Yeah, that and the fix for Intel 945 video used in a lot of netbooks
:-) It works great with just the built in screen, but as soon as you
attach an external display that has a horizontal resolution > 1024 it
breaks, so I need fallback right now.

It is related to 2048x2048 buffer limits in the hardware for 3D.

Quote (http://www.thinkwiki.org/wiki/Xorg_RandR_1.2):
Note that the maximum supported size of the virtual desktop for the
Intel 945GM series of chipset with 3D acceleration enabled, is
2048x2048. The virtual screen can be larger but DRI will be disabled.

(In Fedora 14 this was not so much a problem for use with my external
19" screen as I would just disable the netbook's screen in
gnome-display-properties whenever the external screen attaches. That
way I was able to enable Compiz as long as both screens were not
active at the same time. This does not seem to work in gnome-shell any
more unfortunately.)

François