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XFX Radeon HD 7950 Black Edition Review

Unpacking the XFX HD 7950 Black Edition caused a bit of déjà vu. The card bears a strong resemblance to its big brother, the HD 7970 Black Edition (reviewed April 2012), clad in svelte brushed aluminum. If graphics cards dressed up for black tie galas, then the XFX Black Edition is ready to attend.

XFX pushes the reference clocks higher than stock, hitting 900MHz for the core clock and 1,375MHz for the memory clock. The additional memory cycles translate to a peak memory bandwidth of 5.5 gigabytes per second—the same as the HD 7970, and higher than the 5GB/s of the stock 7950. The question is: Can the GPU keep up? There’s always a balance between memory bandwidth and how much of that bandwidth the GPU cores can actually use. Plus, as more games become shader- and tessellation-intensive, bandwidth isn’t as big a part of the equation.

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Sapphire Radeon HD 7950 OC Review

AMD’s reference HD 7950 board sets its core clock at 800MHz and memory at 1,250MHz, using the default cooling system. Sapphire takes this reference board, adds dual 12cm fans, and juices the core clock to 900MHz. The memory clock remains at 1,250MHz—but that’s 3GB of 1,250MHz GDDR5. Priced at around $480, it’s worth seeing how the card compares with Nvidia’s GTX 580. Note that we’ve also included results from the XFX Radeon HD 7970 for your reference, but excluded that card from the direct comparisons.

For direct comparison we turned to two different versions of the GTX 580—the slightly overclocked EVGA GTX 580 SC with 1.5GB of GDDR5 and the ultra-beefed-up EVGA GTX 580 Classified with 3GB of video RAM—as well as the XFX Radeon HD 7950 Black Edition reviewed next.

The Sapphire card ships with a slight memory bandwidth disadvantage compared with the XFX card (5GB per second versus 5.5GB/s) due to running its GDDR5 frame buffer at the reference clock speed. This shows up in a few benchmarks, where the Sapphire card places just a little behind the XFX card, but the differences are pretty small.

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Asus GeForce GTX 570 DirectCU II Review

ASUS HAS GOTTEN a lot of mileage out of its beefy DirectCU II GPU-cooling technology. It has brought some serious overclocking chops to the GeForce GTX 580 in the form of Asus’s Matrix-branded edition, for example. The DirectCU II versions of the GeForce GTX 560 Ti and the Radeon HD 6870 also sport serious overclocks, and those cards perform well in their respective classes. What’s even better is that the company doesn’t charge much of a price premium for its best cooling tech on cards below the Matrix GTX 580.

We’re scratching our heads, however, over Asus’s decision to offer this GTX 570 card in a three-slot configuration similar to its Matrix GTX 580, but running at Nvidia’s reference clock speeds. The beefy cooler delivers plenty of DIY overclocking potential, but you must assume all the risk. Since we review cards based on out-of-the-box performance, we had to benchmark this one with its 742MHz core clock and 3,800MHz (effective) memory clock.

One good thing the new cooler does provide is fewer decibels. This card isn’t whisper-quiet under load, but it generates much less noise than many of the cards in its class—particularly the Radeon HD 6970, which can get fairly loud under heavy loads.