I do know that Auto cad graphics cards and user GAMING cards are two complelely differant kettles of fish, although I am informed for mainstream CAD work many do use ATI's Radeon, must be that gaming cards are very good value compared to the dedicated and highly expensive CAD specials like the Oxygen.
Depends on wot money your looking at.
ATI's new Radeon 8500 64mb is blowing everything away at the MO, including the latest G/force TI's but just how good they are compared to a dedicated CAD card I don't know. Martin