Tuesday, November 1, 2011



Given Nvidia's success capturing the $200 territory with its GeForce GTX 460 video card earlier this year, it wasn't surprising when the first two cards in AMD's new 6000 series, the Radeon HD 6870and 6850, hovered around that same price. With its newest 6000-series releases, in its high-end single-GPU "Cayman" family, AMD is notching things up next to the next roundest number. While nudging the 6970 to $369 to spar directly with Nvidia's new GTX 570, AMD is also inserting a card into a price range Nvidia doesn't exactly cover: $299. While there's no doubt the Radeon HD 6950 will find a home there among gamers who consider $300 the most a video card should cost, its performance otherwise marks it as a somewhat tough proposition.

The 6950 is a gently scaled-back version of the 6970, offering almost all the same features with just a bit less flair. It packs 2.25 teraflops of compute power and a core clock speed of 800 MHz, both barely shaved off the 6970's 2.7 teraflops and 880-MHz clock speed. The 6950 has the same number of ROPs (32), the same amount of frame buffer (2GB), and a memory path of the same width (256 bits), but fewer stream processors (22 versus 24), texture units (88 versus 96), and reduced memory speed (5 Gbps versus 5.5 Gbps). Both cards also have similar power characteristics: a typical gaming utilization of 140 watts and idle power consumption of 20 watts, though the 6950 requires two six-pin connections from your power supply rather than the one six-pin and one eight-pin the 6970 demands.


The cards are similar in other ways as well. This includes appearance: Except for decals identifying the specific model number, our reference boards for both were identical in every way, including their 11-inch length and their requiring two expansion slots (one for the PCI Express x16 connection and one to accommodate the fan and heat sink assembly). Both cards also have the same display outputs: two DVI (one single-link, one dual-link), two mini DisplayPort jacks, and one HDMI connector, letting the user connect a maximum of six displays for taking advantage of AMD's much-touted Eyefinity multimonitor display technology.

Like its bigger brother, the 6950 supports the full range of DirectX 11 (DX11) rendering capabilities, such as tessellation. It also sports expanded anti-aliasing support, with the 6000 series' new Morphological Anti-Aliasing now joined by an Enhanced Quality Anti-Aliasing (EQAA) mode: EQAA can have up to 16 coverage samples per pixel, is compatible with adaptive and super-sample anti-aliasing, and AMD claims it offers better quality for the same memory cost. The 6970 also introduces AMD's PowerTune technology, which aids in overclocking by letting the user specify a maximum TDP (up to 200 watts) at which to constrain power usage and maintain peak performance over a longer stretch of time.

With gaming video cards, however, it's performance that counts most, and that's where the 6950 starts looking mighty curious. The primary problem—and, we assume, why AMD has priced this card as it has—is that Nvidia doesn't have a current product that directly competes at $300. So to place the 6950 in terms of performance, we need to look at similar (and still-available) Nvidia releases from the last and current generation.

As of this writing, cards based on Nvidia's GTX 470 chipset (the second-most-powerful first-generation Fermi GPU) are available for as little as $229 after mail-in rebates, or about $249-$259 before them. Against a Galaxy GTX 470 factory overclocked to 625 MHz ($229 after rebate), the 6950 scores decisive victories in only two tests: both in the Heaven Benchmark 2.1 at 2,560 by 1,600, and using both DX10 and DX11 shaders. The 6950's scores of 30.9 frames per second (fps) with DX10 and 16.9 fps with DX11 (versus 12.3 fps and 9.1 fps) are likely because it has nearly double the GTX 470's frame buffer (1,280 MB). In every other case, the 470 either body-slammed the 6950 (122 fps at 1,920 by 1,200 and 63 fps at 2,560 by 1,600, in H.A.W.X. 2, versus 83 fps and 53 fps for the 6950), did comfortably better (43.7 fps versus 36.7 fps in Lost Planet 2 at 1,920 by 1,200), or merely outperformed the 6950 above its price differential. The 6950 improves somewhat if you consider the cards' base prices of $249 and $259 instead, but even then the GTX 470 beats the board on 17 and 14 of our 26 tests, respectively.

Looking instead at the recently released GTX 570, which lists for only $50 more than the 6950, the picture is somewhat rosier. The 6950 does better on our 2,560-by-1,600 tests in the Heaven Benchmark and Metro 2033, and overshoots the price-performance threshold more often than not. But it can't keep up in H.A.W.X. 2 (the GTX 570's 153 fps at 1,920 by 1,200 and 78 fps at 2,560 by 1,600 are killers) and Lost Planet 2 (the GTX 570 is a minimum of 23 percent faster, and often quite a bit more than that)—unfortunately the two of our benchmarks that most accurately simulate real-world playing conditions in new, DX11-heavy titles.

That puts the AMD Radeon HD 6950 in a tough spot: It may have an attractive-on-paper price, but it too often lacks the performance to match. If you want a more powerful card for not a lot more money, you can scrounge your sofa cushions for another $50, pick up an Nvidia GeForce GTX 570, and get better results in almost any title. If $300 is your hard ceiling, many GTX 470s are available for much less and will do the job admirably in most cases; they will deliver more bang for your buck and speedier frame rates than the 6950 in key DX11-drenched titles—and you'll get a still bigger boost if you opt for a heavily overclocked GTX 470 instead. Most models of which top out on Newegg at $299 and are clocked well beyond our Galaxy version. The 6950 is a decent card, but its difficulty finding a comfortable position near the bottom end of the semi-hard-core enthusiast spectrum might be the reason there was a $300 slot there to fill.

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