Sapphire has 4 versions of the X800 GTO, the GTO, the GTO2, the Fireblade and the Ultimate.  HardwareZone tested all 4, and you can see their results here.
“Sapphire dropped a bombshell on us with its complete range of Radeon X800 GTO 256MB cards for the PCI Express interface. Consisting of four similarly clocked cards that target different users, the lineup is very comprehensive. We tested the entire convoy of cards, so read on and see what we found”

Here are some more Graphics Card articles from around the web:

Click Here to go to Video Cards   Graphics Cards