Sapphire HD 7970 OC
Sapphire’s HD 7970 OC is the company's top-of-the-line option, currently selling for $479.99 on Newegg (Update [6/1/2012]: Newegg recently jacked the price up to $580, destroying this card's originally-cited value. If you're interested in this board, we'd recommend shopping around.). At 11.5” by 5” x 1.75”, it's the thickest card in our competition, eating up slightly more than two expansion slots. Despite its width, the HD 7970 OC weighs 1 lb 14 oz, making it the second-lightest board in our round-up. That's less than AMD's reference design, even.
Rather than using the Radeon HD 7970's second firmware as a backup, Sapphire chose to do something else with AMD's BIOS switch, allowing enthusiasts their choice between an already-overclocked 950 MHz core and 1425 MHz memory frequency, or a more aggressive 1000 MHz GPU and 1450 MHz memory clock. This is a neat way to allow enthusiasts to easily squeeze more performance out of their hardware with the flip of a switch, literally.
As an aside, Sapphire’s submission sports the fastest factory memory clock of any Radeon HD 7970 we’ve seen. And yet, The card requires the same six- and eight-pin auxiliary power connectors as AMD's reference model.
The Dual-X cooler features two 90 mm axial-flow fans, three 6 mm and two 8 mm copper heat pipes, a copper block, and aluminum cooling fins. The shroud is plastic, but nicely detailed and stylized.
Sapphire opts for AMD's default output configuration, consisting of one dual-DVI port, HDMI, and a pair of mini-DisplayPort connectors.
Sapphire’s 7970 OC bundle includes a CrossFire bridge, a DVI-to-VGA adapter, an HDMI-to-DVI adapter, a mini-DisplayPort-to-DVI adapter, a mini-DisplayPort-to-DisplayPort adapter, a four-pin Molex-to-six-pin auxiliary adapter, a dual four-pin Molex-to-eight-pin auxiliary adapter, a software install CD, a quick-install guide, and a registration card. This is by far the most robust bundle in our round-up, and it'll accommodate a triple-monitor DVI-based setup right out of the box. Sapphire earns our praise for its value-added inclusions.
Overclocking Sapphire's HD 7970 OC
Sapphire's TriXX overclocking utility is a great little program that clearly comes from the same developers as HIS’ iTurbo app; both offer similar options, but with different skins. This isn’t a problem, since the two programs work well. Again, though, we're missing support for AMD's PowerTune technology, so we have to max it out at +20% in Catalyst Control Center to prevent the clocks from throttling back under load.
Whereas Catalyst Control Center's Overdrive applet tops out at 1125 MHz core and 1575 MHz memory clocks, the TriXX utility allows adjustments up to 1500 MHz and 2100 MHz, respectively, with a 1.3 V maximum voltage.
We were able to push Sapphire's card to a stable 1175 MHz core and 1800 MHz memory overclock at 1.2 V.