Gnome 3 vs scientists (ie., external monitor problem)

[Jan Skowron <jan skowron gmail com>]

Hello,
I am writing to ask: which exact parameter of a graphics card decides
about the maximal resolution card can handle in 3d accelerated mode
(needed for Gnome 3)?
I couldn't find this on the Gnome 3 web page. Could you add a link to
such information in the FAQ section where talking about the graphics
requirements?

In the FAQ I have found only a very approximate information which
cards are supported. I agree that this is good enough information for
the first time visit where someone wants to learn about Gnome 3.
However for every specific person deciding to try or not Gnome 3,
those details make a huge difference.

As a scientist I can tell that use of an external monitor with a
laptop is essential to my work. When I am plugging the projector in
before a lecture I am not rebooting my system of course. But the
resolution of the desktop suddenly increases from 1280 to grater than
2048px. This can create an unintended mess in Gnome 3 since, as I have
heard, many (most) common graphics card does not have power to
accelerate more than
this. Plugging external monitor without reboot is a very common use
case, and Gnome 3 cannot handle this
correctly, so it would be nice to communicate this to users prior the
installation or potential disappointment. Additionally it will not
look good in the eyes of students -- potential future developers,
contributors, supporters, .... or not.

I would like to have a way to check if my graphics card can handle
Gnome 3 on 2 displays, ie., with resolution grater than 2048px by
2048px.
The link to a howto would be very useful on
http://live.gnome.org/GnomeShell/FAQ and
http://live.gnome.org/GNOME3Myths
Also, if one have learned that his card would not sustain external
monitor, how he would disable the standard Gnome Shell and set
fallback as a default option? This information would be useful as well (in a
FAQ or so) to avoid problems/confusion/waste of time every time the
projector or monitor is plugged in or intended to be plugged in.

Does one of these options decide about the maximal resolution?:
GL_MAX_TEXTURE_SIZE
GL_MAX_RECTANGLE_TEXTURE_SIZE
or GL_MAX_CUBE_MAP_TEXTURE_SIZE

if yes, how to check what is the value of these for the installed card
on ones computer?

Thanks in advance for any help,
Jan Skowron