Sapphire's Radeon R9 280: Still Competitive
AMD has a rich history of iterating its Tahiti GPU in the 1792-shader configuration, from the 800 MHz Radeon HD 7950 to the 933 MHz (peak) Radeon R9 280. Of course, all of those cards use 1250 MHz (5 GT/s effective) GDDR5 memory. The upcoming Radeon R9 285 marks the first bump in memory clock for this class of AMD card at 1375 MHz (5.5 GT/s effective, the same as the Radeon HD 7970), but this is more than offset by a thinner 256-bit memory interface, and its maximum GPU boost clock rate drops slightly to 918 MHz.
With a 940 MHz peak frequency, Sapphire's Dual-X R9 280 OC has the highest GPU clock rate of any of these options, although it beats the reference Radeon R9 280 by a mere 7 MHz. That doesn't sound like much, but keep in mind that the real-world clock rate is limited by temperature. Sapphire's real strength isn't the overclock; what matters is whether or not the Dual-X cooler has the ability to control the thermal ceiling in order to keep the GPU running at the highest possible frequency for as long as possible.
Sapphire's Dual-X R9 280 OC sports the unique Dual-X cooler with a black-on-gray theme, attached to the company's namesake-colored PCB. That board measures 10.25" x 3.89" and weighs 1 lb 10 oz, making it slightly smaller and significantly lighter than AMD's reference Radeon HD 7950 Boost card at 10.5" x 3.89" and 2 lbs.
This particular product's graphics processor is rated for 850 MHz base, with a boost state of 940 MHz, and 1250 MHz GDDR5 memory. The amount of memory used on Tahiti-based boards is at least generous 3 GB, and the Dual-X is no exception.
The aluminum heatsink features four beefy 8 mm copper pipes, cooled by two 85 mm low-profile fans. The card's 250 W TDP requires two six-pin auxiliary power connectors.
Note the two CrossFire connectors on the right, allowing as many as four cards to render cooperatively. A Dual BIOS switch allows the user to select either legacy or UEFI compatibility modes. As an added bonus, it also provides a measure of safety for those who like to tweak their cards with a ROM flash.
The Dual-X R9 280 is equipped with a DVI-I, DVI-D, full-sized DisplayPort, and full-sized HDMI output.
The package includes a CrossFire bridge, a six-foot HDMI cable, two Molex-to-six-pin PCIe power adapters, manual, registration card, driver CD, and case sticker.
Now that we're familiar with the product, let's see how it performs.