Calling the smart doctor
Here's the card in default mode, clocked in at 850MHz engine and 3,900MHz memory. Note the 1.312V and fan-speed (when idling) of around 1,000rpm. It's barely audible in this state.
Overriding the fan's setting to eliminate cooling-related issues and cranking up the voltage to a maximum of 1.45V, we managed to hit a stable 986MHz engine and 4,680MHz memory. Bear in mind that our numbers are on the conservative side. Using an identical setup, we hit 965MHz engine and 4,700MHz memory with the Sapphire Radeon HD 4890 OC+ and 940MHz/4,600MHz with a standard-clocked card. The Sapphire HD 4890 ATOMIC ships with a 1,000MHz, as we noted earlier.
It does get rather noisy when the fan-speed is ramped up, but it's intrinsically difficult to hit high frequencies with near-silent cooling, clearly.
On to special-edition card number two.
