rustler: problem is that each manufacturer adds some speials on those cards.. There are many opinions (like dualhead, DVI output, video output, Video input, TV tuner etc) that are not available on all cards. And besides .. same gfx chip can usually be configured to different amoun, speed and type of Display memory...
And then.. making it even more fun.. different manufacturers (sellers) tend to name those additions differently.. So ofthen it's not only Gfx chip that differs..
