http://www.overclockers.co.uk/acatalog/X800_Pro.html
the HIS Excalibur ICEQ2's on that page (or any site that sells them ) r software locked to be x800 pro's
meaning they r actually x800 XT's ( the top ati card) the gpu or the memory (can't remember which) speed is 1 or 2 mhz slower than the x800 XT's which is why they r rated as pro's
all the other make's (that i know of) hardware lock this card card to be a x800 pro mean they cut the extra 4 piplines which make the card into a XT, HIS don't they leave the piplines intact and only use software to make it a x800 pro.
which is quite easy to fix
plus the his x800 pro's r fited with a custom heat sink fan thingy which r as good as the ones on the stanard xt's
note: this is all from memory so i maybe off on a few details
i think i'm rite tho