Review: AMD Radeon HD 6850

AMD's Radeon HD 6870 hit the streets yesterday along with this, the cut-clocked Radeon HD 6850. But where does the smart money go?A lot can happen in twenty-four hours. And indeed a genre-shifting amount has come to pass since yesterday in the frenetic world of graphics cards. As ever, it all comes down to money.Read our AMD Radeon HD 6870 reviewIn light of AMD's impending launch of it's second-generation DX11 graphics card, Nvidia slashed the prices of its GTX 460 and GTX 470 graphics cards. AMD then launched its 6870 and 6850, quickly followed by a similar slashing of its pricing. This has meant there is a surprising gamut of prices being charged for the 6850 ? ranging from �133 up to �159. For this reason we've held off on our 6850 review until now, as we're sure that the dust is finally starting to settle.AMD is pitching the Radeon HD 6850 as "the best performing graphics card in the sub-$200 budget." In other words pricing is absolutely key to the very reason for this card. The problem is, thanks to Nvidia's shenanigans, it's finding itself squeezed from above and below, trapped (price-wise at least) between the 768MB rendition of Nvidia's GTX 460 (available for as little as �117) and the full 1GB variant. It needs to pull some serious magic out of its svelte silicon to compete there.The AMD Radeon HD 6850 doesn't boast a completely new core though, more of a revamped version of the Cypress core, as found in the HD 5850. Codenamed Barts Pro, the 6850's core has 960 stream processors, running at 775MHz. That's two-thirds of the shaders you'll find in the 5850, a difference the 50MHz faster clock speed is ill-equipped to make up. The fact that AMD can run this core at higher clock speeds is due to a smaller die-size, 255mm2 as opposed to the 334mm2 found on the previous generation. You do get the full 32 ROPS mind, plus a slightly overhauled tessellation engine that improves performance at the more reasonable tessellation factors.The 6870 and 6850 boast a new anti-aliasing mode too, termed MorphoLogical Anti-aliasing, or MLAA for short. The interesting thing here is that it uses DirectCompute to process the full scene after it has been rendered, to produce results similar to 4x MSAA but faster and at a reduced memory footprint. There have been some improvements to the anistropic filtering engine too to smooth the transition between different levels of detail to reduce the effects of stepping. Subtle improvements then, but improvements all the same.In terms of the core specification then, the AMD Radeon HD 6850 (note that dropping of the ATI branding, it's not a mistake) ships at a core frequency of 775MHz coupled with 1GB of GDDR5 running at 1,000MHz (effectively 4GHz). You'll need a single six-pin power cable for this dual-slot card, and you're good to go. You can expect card manufacturers to produce overclocked, non-reference design versions from the get-go too.The Radeon HD 6850 has been blessed by some last minute price shuffling to make it a much more interesting proposition that it was initially (AMD has shaved �30 off the price of the card). Even so, against the slightly more affordable GTX 460 768MB it struggles to impress in our tests ? losing out in our top three benchmarks. Only the Heaven 2.0 benchmark really puts the card in a good light, thanks to the improved tessellation engine. All benchmarks ran at 1,680 x 1,050 and the highest settings.DirectX 11 Tessellation PerformanceDirectX 11 Gaming PerformanceDirectX 10 Gaming PerformanceThe AMD Radeon HD 6850 isn't quite the must-buy card that we expected it to be, especially at its initial pricing. Now that the dust has settled a little on the pricing front it's a much a more interesting prospect, producing playable frame rates at what would have been the sweet spot for most gamers only a few days ago. It's certainly not the worst graphics option out there.Graphics cards aren't released into a vacuum though, and you're spoiled for choice if you've got between �100 and �150 to spend on your next graphics card. The 6850 finds itself sandwiched between the two 460s, which makes for some tricky comparisons. It's not woefully out-matched, but those that can afford the shift up to a 1GB GTX 460 will reap the benefits, whilst a �20 saving and plumping for the 768 version produces similar performance. Ultimately, which card you go for it largely defined by the value you place on the likes of Physx, CUDA and Eyefinity.The spectre of Cayman-powered Radeon 6900s isn't a direct threat to the 6850, as such cards will undoubtedly appear north of the �200 barrier. Even so, their release may have Nvidia cutting into its margins yet again, something that the 6850 looks ill-placed to weather. We liked:Rolls in at the right price point (eventually), producing playable framerates in most recent games. Power consumption is low, as is noise production ? although under full load it does reach a heady 81oC on the stock cooler.We disliked:Value for money lags behind the GeForce GTX 460s, and in straight cash terms a better bargain can be had in the form of the 768MB GTX 460. The reduced shader count affects raw performance too much, especially given the marginal frequency increase over its predecessors.Related LinksTechRadar's Review GuaranteeRead more graphics card reviewsRelated StoriesMSI R6800 series graphics cards announcedHIS releases Radeon HD 6850 and 6970 graphics cardsAsus unveiled EAH6800 graphics cardsAsus unveils EAH6800 graphics cardsIn Depth: Can Nvidia compete with AMD's new graphics chips?Choosing the right Golf Clubs