Gigabyte’s flagship Radeon HD 7970-based board employs a custom black PCB. Measuring 10.5” long, 4.75” tall, and 1.5” thick (not including the bezel), and weighing 1 lb 10.6 oz, this is the smallest and lightest card in our round-up. At press time, the GV-R797OC-3GD sells for an even $500 bucks on Newegg.
This card boasts a core clock of 1000 MHz core and memory running at 1375 MHz; that’s a 75 MHz GPU boost complemented by memory running at AMD's reference specification. Also like the reference model, Gigabyte's R797OC-3GD requires one six-pin and one eight-pin auxiliary power connector.
At first glance, this card's cooler appears to be fairly typical of what we've seen from Gigabyte in the past, with three 80 mm axial fans blowing over a trio of 8 mm heat pipes, all covered in a plastic shroud. The company claims that a new heat sink structure minimizes turbulence between the fans and provides better cooling efficiency. Of course, that sounds nice, but we need to put it through our test regimen in order to gauge the true improvement.
Gigabyte employs the same dual-link DVI, HDMI, and twin mini-DisplayPort outputs as AMD's reference design.
The company includes a CrossFire bridge, a DVI-to-VGA adapter, a dual four-pin Molex-to-six-pin power adapter, dual four-pin Molex-to-eight-pin power adapter, a driver disk, and a user guide.
Gigabyte covers the basics; however, we think that all Radeon HD 7970s should come with at least one mini-DisplayPort-to-DVI and one HDMI-to-DVI adapter for the folks interested in exploiting Eyefinity on the desktop. DisplayPort and HDMI are both less prevalent in that space.
Overclocking Gigabyte's R797OC-3GD
Gigabyte relies on AMD's Catalyst Control Center’s Overdrive feature for overclocking, though it enjoys an elevated 1200 MHz core and 1600 MHz memory limit.
MSI’s vendor-agnostic Afterburner software is even more generous in its ceilings, facilitating 1800 and 2475 MHz core and memory limits, with a voltage slider that tops out at 1.3 V.
We were able to stably overclock our sample to 1200 MHz and 1600 MHz for the core and memory, respectively, using a 1.25 V setting.