AMD Radeon HD 7970: 28nm Tahiti GPU Review
AMD Radeon HD 7970 Card
Although it bears some resemblance to previous-generation Radeon HD series cards and sports a similar red and black color scheme, the Radeon HD 7970 has a number of new tricks under its fan shroud; for AMD at least.
As you can see in the images above, the card is roughly the same size as a Radeon HD 6970 at 10.5”. There is a single, barrel type fan at the rear of the card, which pumps air through a heatsink with a vapor chamber, and is ultimately expelled through vents in the case bracket. That’s how previous Radeon HD 6900 series cards were configured as well, but with the 7970, AMD has moved to a new fan design with larger, wider blades. The fan has been optimized for lower RPMs for better acoustics, but pushes more air. AMD also removed the stacked DVI connector to increase the size of the exhaust vent and reduce turbulence. The Radeon HD 7970 is also outfitted with a multi-step vapor chamber with three distinct levels. One level makes contact with the GPU, another the memory, and the last touches the VREGs.
The fan shroud design has been tweaked as well. Unlike Radeon HD 6900 series cards which had a mostly squared, flat design, that was sealed at the rear, the Radeon HD 7970 has a curved shroud with additional vents. AMD also removed the stiffening plate from the back to maximize the amount of air-space that would be present between cards installed in adjacent PEG slots.
AMD also uses a second-generation phase-change thermal interface material, all of which culminates in significantly reduced temperatures over older Radeons. In fact, we never saw a GPU temperature above 65 degrees, but honestly we’re not confident OverDrive was reporting GPU temps properly.
Other physical attributes of the Radeon HD 7970 include the familiar pair of CrossFire edge connectors, and the two-position BIOS switch that debuted on Radeon HD 6900 series cards. That tiny switch is used to toggle between two BIOS chips on the card—the first BIOS can be altered / updated, while the second will return the card to its factory settings. That’s something that might come in handy with the modding crowd.
Also on the top, at the far end of the card are its power connectors. The Radeon HD 7970 requires two supplemental power feeds, a PCIe 8-pin feed and a 6-pin as well. Finally, the output configuration on reference Radeon HD 7970 series cards consists of one dual-link DVI output, two mini-DisplayPort outputs and a single HDMI output. Four of these outputs can be used at any given time to power displays in a multi-monitor Eyefinity configuration, but with upcoming DisplayPort hubs due to arrive next year, up to six displays can be connected.