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.
‘We don’t need no stinkin’ reference design!’ says XFX
It's not unusual to see factory-overclocked videocards ship with custom cooling solutions a few months after a GPU launches. But XFX didn’t waste any time with its Radeon HD 7970 Black Edition—a factory-overclocked card with a custom cooling solution that aims to take the performance crown. Based on what we’ve seen to date, XFX has delivered the fastest single-GPU card on the planet.
The Radeon HD 7970 is AMD’s latest GPU, with support for DirectX 11.1 and OpenCL 1.2. It’s a brand-new architecture—completely different from past AMD GPUs—built on TSMC’s 28nm manufacturing process and sporting a staggering 4.3 billion transistors. In AMD’s reference design, the 7970’s core runs at 925MHz, and its GDDR5 memory is clocked at 1,375MHz. XFX ups the ante significantly, pushing the core clock speed to a whopping 1GHz and running its 3GB of memory at 1,425MHz.
As you might imagine, the results are nothing short of amazing. We’re seeing genuine performance milestones here, including a 3DMark 11 performance score higher than 8,000 (for a single GPU), Far Cry 2 hitting 100fps at 2560x1600 with 4x AA, and Batman: Arkham City heading north of 50fps at the same resolution and AA settings. On top of that, the idle system power is just 124 watts, and a dark idle (when Windows 7 blanks the screen) draws 110 watts. Push the card and you’ll see system power consumption climb to 349 watts, but that merely puts its overall power draw into Fermi territory. XFX’s Radeon HD 7970 Black Edition is substantially faster than EVGA’s super-overclocked 3GB GeForce GTX 580 Classified, and it’s outfitted with just two PCIe power connectors (one 8-pin and one 6-pin). EVGA’s card requires three power connectors.
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.
You can't hardly buy a processor any more without also purchasing a graphics chip. That's because many of today's CPUs sport integrated graphics, a relatively new development as both AMD and Intel push their respective CPU+GPU solutions onto the masses. But despite each company's efforts, along with a constant flow of discrete GPU solutions from AMD and Nvidia, graphics shipments are down overall.
Nvidia’s new Kepler-based graphics cards are still fairly new on the scene, but a fairly serious new bug has emerged that started out as a forum rant, and has evolved into an official acknowledgement from the green team. The problem in question seems to be limited to GTX 670, 680, & 690 customers who enable v-sync though the Nvidia control panel, and by most accounts, is pretty infuriating.
Nvidia President and Chief Financial Officer Jen-Hsun Huang gleefully indicated that "Kepler GPUs are accelerating our business" when reporting revenue of $924.9 million for the company's first quarter of fiscal 2013 ended April 29, 2012. The irony there is that Kepler cards are in short supply and extremely difficult to find in stock, save for the GeForce GTX 670, which just went on sale yesterday. But despite GPU shortages (courtesy of TSMC's inability to produce chips fast enough), Nvidia was able to best analysts' expectations.
Taiwan Semiconductor Manufacturing Company (TSMC) may have underestimated the challenges involved with churning out 28nm parts, or perhaps the company is simply inundated with orders. In the end, it doesn't really matter what the problem is, as far as clients go, and when Nvidia reportedly threatened to place orders with TSMC's competitors, suddenly the GPU maker was bumped to the front of the line.
It's still a challenge finding one of Nvidia's Kepler infused GeForce GTX 680 graphics cards in stock and ready to ship, but one thing the new GPU series doesn't lack is third-party variation. Nvidia's GPU partners are putting their own stamp on the GTX 680 with custom coolers and, in some cases like the new DirectCU II TOP edition from Asus, custom designed PCBs as well.
All right, the Nvidia GTX 680 is finally here, and it's awesome! The high end graphics card is so awesome, in fact, that picking one up will set you back a cool $500 -- more than many people are willing (or able) to spend on gaming. Fortunately for fraggers on a budget, we're starting to hear rumors about more moderately priced cards like the GTX 670 Ti.
Overclocking a graphics card isn't terribly difficult, and if you're careful, it's not all that dangerous either. But there's always that risk of taking things too far or ending up with components that just don't respond well to faster clockspeeds. Factory overclocked cards get around both problems, and one of the newest on the market is TUL Corporation's PowerColor PCS+ HD7850, a spiffy looking hunk of hardware with a power friendly design.