Graphics: Diamond Radeon HD 6870 (6870PE51GXOC)
By: William Van Winkle
In situations like this, it can look like we’re playing favorites, so let’s just be up front. There is very little difference between the Radeon HD 6870 cards out today. When you’ve seen one, you’ve seen most of ‘em. We picked Diamond’s XOC because it comes overclocked from the factory, giving us a little extra performance to make up for the shaders that AMD's Barts GPU sacrifices compared to last-generation's Radeon HD 5870. Believe it or not, there aren't as many factory-overclocked boards out there right now, and it looks like Diamond's is the fastest at 940 MHz (one other vendor has a 940 MHz board, too).
The 6870 GPU does what AMD does best: deliver a lot of features and horsepower at a compelling price point. But in recommending the Diamond card here, we’re really suggesting that Santa stuff stockings with the 6870, not necessarily this or that incarnation of it. Admittedly, we give the 6800-series an endorsement with a caveat. When you watch the model numbers and assume that bigger is better, the 6870 looks like AMD’s current flagship. Technically, it is the company's newest single-GPU offering. But the reality is that the 6870 underperforms the older 5870 and more closely resembles the 5850, both in performance and the $250-ish street price tag. Where the 6870 really seems to take off is in a CrossFire configuration, allowing it to beat the pants off of competing $500 boards like the Radeon HD 5970 and GeForce GTX 580.
The 6870 features fewer shader processors than AMD's Radeon HD 5850 (1120 vs. 1440), texture units (56 vs. 72), and transistors (1.7 vs. 2.15 billion). However, the 6870 boasts a slightly faster GDDR5 memory data rate (1050 MHz) and GPU core clock (900 MHz default vs. the 5850’s 725 MHz). With Diamond’s XOC, you get a respectable boost to 940 MHz and a memory clock hop to 1100 MHz. The end result of this give-and-take routine is that the 6870 XOC can squeeze past the 5850 in many tests.
If performance is a push, that leaves features as the real reason to love AMD's Radeon HD 6800-series. And that's ultimately the real reason we'd spring for a Barts board over a Cypress-based card. At last, AMD arrives with its own open 3D technology, dubbed HD3D. Now we just need compatible monitors to go with it. OK, so stereoscopic support is probably a bad example of what the 6800s can do well. The 6800-series also supports 3D Blu-ray movies when you hook up to a compatible HDMI 1.4a-based receiver. A new morphological AA mode provides another option for smoothing out jaggies without bogging down performance. Perhaps more importantly, the update to DisplayPort 1.2 compatibility means that Eyefinity can finally utilize video hubs to output multiple discrete video streams from a single port. On Diamond’s XOC card, you get five ports—two DisplayPort, one HDMI, one dual-link DVI, and one single-link DVI. Quad-monitor display output is now possible through the two DisplayPorts, along with two of the three remaining digital connectors.
In most other ways, the 6000 series echoes the 5000 series, including support for DirectX 11 and some exemplary HD video playback capabilities. Don’t look for any extras in Diamond’s box beyond a CrossFire bridge interconnect, and make sure your PSU has two six-pin auxiliary power connectors available. If you don’t want to break the bank on a graphics and video upgrade this holiday season, Diamond’s Radeon 6870PE51GXOC is your best play.