Workstation GPUs are tending to be very simialr to gaming ones these days, but with extra support and features turned on via the drivers (often in conjuntion with the card). This has, in the past, made it possible to hack a GeForce series card into reporting itself to the drivers as a Quadra.
The additional features tend to be specific to the Workstation market, i.e. hardware anti-aliased lines for CAD usage.