nvidia and dri

[howarth bromo msbb uc edu (Jack Howarth)]

     I have been using ATI's non-free drivers in the past so this
week was the first time I have had a chance to install the Nvidia
non-free drivers on FC4 x86_64. While I was able to setup it up
without problems, one issue puzzles me. Their instructions are
to disable the dri module. Does this mean the Nvidia non-free
drivers don't use dri like the ATI non-free drivers do? Is there
any opengl performance impact from this? Thanks in advance for
any clarifications.
            Jack