Well, you can trust the log for that, if you need to make sure, you can
also use fglrxinfo or glxinfo to determine whether Direct Rendering is
enabled or not. If you get someting like OpenGL Renderer String: ATI
Radeon 9600XT or something like that, you are using DRI, if MESA shows
up, you are using software OpenGL.
The internal and external AGPGART drivers in the fglrx module only makes
a difference when you have hardware that is not recognized by the
driver's GART driver. In otherwords, if you have a chipset for which the
driver doesn't know how to operate AGPGART on. In such cases you are
forced to use the External module which would correspond to the
kernel-side driver.
