How to get working dual head on Intel GM965/GL960 under Linux?

"Here's Intel's own tutorial.

Finer points:

you'll probably first want to set up virtual screen size

# This optional entry specifies the virtual screen resolution to be used.
# If this entry is not present, the virtual screen resolution will be set to
# accommodate all the valid video modes given in the Modes entry.
# There is a known issue that DRI doesn't work on pre-965 if maximum is larger than 2048x2048.
Virtual 2048 2048

then you can try setting with xrandr that the ""other"" screen is RightOf of the primary screen

xrandr --output VGA --left-of LVDS

finally you can statically reconfigure it all in xorg.conf. Refer to Intel's tutorial

This worked for me on my 915GM (a.k.a. GMA900).

Rant follows:

By the way, sticking with old Intel's drivers is not a good idea just because you like KDE3.5. They're undergoing a nice rewrite at the moment, with reduced performance, but also with a promise of better capabilities and performance in the future. I remember I
had problems with dualhead back in 2008. This is just my personal opinion however.

Also, you may be interested in fact that latest GNOME (at least, latest in Debian) has much nicer support for dualhead displays."