Remember the Radeon HD 5830? That videocard filled a certain price point, but it was actually the same GPU used in the high-end HD 5870, with a large chunk of the die disabled. The net result was a graphics card that was physically bigger than the intermediate HD 5850 and used more power. And although it cost less, performance really wasn’t up to snuff for the target price point.

Enter the Radeon HD 6790. At first blush, it’s similar in concept to the HD 5830. AMD took its Barts GPU (used in the Radeon HD 6870 and 6850) and disabled a big chunk of it. Voilà: the Radeon HD 6790. The card requires two 6-pin PCI-E power connectors, while the beefier HD 6850 only needs one. AMD told us this was necessary due to the HD 6790’s higher core clocks and voltages.

Sapphire’s Radeon HD 6790 is surprisingly capable, but still an oddball GPU.

We’re being a little unfair, though, because AMD (and Sapphire, which makes this particular model of the HD 6790) is setting a more appropriate price for the performance, particularly when compared to its direct competition, the Nvidia GTX 550 Ti.

The problem, however, isn’t how it fares against the 550 Ti. Rather, it’s the fact that for a few dollars more, you can get faster cards. On the one hand, you can find Radeon HD 6850 cards, which typically require only a single power connector, for about $20 to $25 more. On the other hand, you can still find 768MB Nvidia GTX 460 cards for around $160—just a $10 increase.

It’s worth noting that the Zotac GTX 550 Ti used in our comparison is factory overclocked to 1GHz—fully 100MHz higher than the factory default. (Does “factory default” even have a meaning anymore?) The Sapphire card is running at the stock 840MHz.

When you look at performance, the Sapphire looks like a pretty decent choice, particularly for single 1080p displays. At 1920x1200, with 4x AA enabled, it managed respectable frame rates in some games, and generally overpowered the overclocked Zotac. It does use a little more power at idle, but is more efficient at full throttle, which is pretty typical of AMD parts. The 6790 seems a bit bulky for its class, but should fit in most PC cases. The Sapphire HD 6790 ships with two DVI ports (one is single-link), one full-size DisplayPort 1.2 connector, and an HDMI 1.4a port. The card can fully support three displays, though if you want three 30-inch monsters, they’ll need DisplayPort 1.2 capability.

In the end, Sapphire’s Radeon HD 6790 offers decent enough performance in its class, but bear in mind, for just a few bucks more, you can pick up an HD 6850.

$150, www.sapphiretech.com