ATI: Linux vs. Windows Vista
 

Since AMD introduced their new Linux display driver last
month, we have published a number of different articles looking at the
Radeon performance across their different GPU product generations. This
ATI/AMD Linux driver testing and exploration continued this month with
the release of the 8.42 driver, which finally introduced AIGLX support
for the fglrx driver. One area though we haven't yet analyzed is how
their official Linux driver now compares to their much-optimized Windows
Catalyst driver. Today, however, we will be looking just at that as we
compare the ATI Radeon HD 2900XT 512MB performance under Linux and
Microsoft Windows Vista.

http://www.phoronix.com/vr.php?view=11337