https://bugs.freedesktop.org/show_bug.cgi?id=28402

--- Comment #72 from Michel Dänzer michel@daenzer.net 2010-09-21 05:42:43 PDT --- (In reply to comment #71)

[drm] AGP mode requested: 1

[...]

[...] I wonder why I get 1x automatically.

The line above means you have (the equivalent of) radeon.agpmode=1 somewhere, either on the kernel command line or maybe in /etc/modprobe.d/ . Without an explicit option, the default is determined by the BIOS and can sometimes be tweaked in the BIOS setup.