Don't be fooled by the Radeon HD 6850's spot on the totem pole. It may sit at the lower end of AMD's new 6800 series, but this card is more than a match for the GPU it ostensibly replaces, and even gives the beefier Radeon HD 5850 a run for its money. Coming in at £159, the Radeon HD 6850 might not top the charts, but it offers an excellent price-to-performance ratio that's sure to please the frugal gamer.

Like the larger Radeon HD 6870, the Radeon HD 6850 is built on a new chip architecture, codenamed Barts. That's a modified version of the chip architecture powering the Radeon HD 5850 and 5870 graphics cards (dubbed Cypress). The new architecture cuts back on size, but still delivers performance in spades.

Aesthetically, the Radeon HD 6850 is nearly identical (albeit a bit shorter) to the 6870. Both cards are equipped with AMD's Eyefinity Technology, which will allow you to drive up to three displays from a single card. They sport a pair of DVI ports (one dual-link and one single-link), an HDMI port and two mini-DisplayPort connectors, you'll need a pair of adapters to make use of them.

We'll be comparing the Radeon HD 6850 to the Radeon HD 5770, which is its closest relative at around £120. On our synthetic benchmark tests, the 6850 defeats the 5770 soundly. Perhaps more impressively, it doesn't lag too far behind the Radeon HD 5850, which will set you back at least an extra £50. On the Unigine Heaven benchmark the 6850 consistently leads by one or two frames per second, thanks in no small part to the 6800 series' improved tessellation engine. While synthetic benchmarks are necessarily indicative of real world performance, they're a fair barometer of how the GPUs stack up.

Games testing paints an ever rosier picture for the 6850. While it still sits behind the Radeon HD 5850, it doesn't lag by much. Tom Clancy's H.A.W.X. offers the greatest divide with an average lead of 16 frames per second, not bad for a £50 discount, and the gap shrinks once anti-aliasing is enabled.

The Radeon HD 5770 is a smaller card, and as such demands less power under full load: 200 watts, versus 219 watts for the 6850. The 6850 demands less power when idle, 102 watts, versus 105 watts for the 5770. But once we take overall power efficiency into account and weigh the cards by their performance per watt, the positions are reversed: the slower 5770 becomes the least efficient.

OUR VERDICT

AMD's Radeon 6850 may not lead the pack, but from a value standpoint, its price-to-performance ratio is tough to beat. An aggressive price tag is coupled with excellent gaming performance, challenging even the impressive Radeon HD 5850. If your budget is tight but you refuse to skimp on performance, your graphics card has arrived.