Enthusiasts want to know about Nvidia's next-generation
architecture so badly that they broke into our content management system
and took the data to be used for today's launch. Now we can really
answer how Kepler fares against AMD's GCN architecture.
Nvidia is fond of drawing parallels. With its
prior-generation graphics cards, the company likened each model to a
different role on a virtual battlefield. GeForce GTX 480 was the
tank—big performance and, to a fault, a big price, big power, and big
heat, as well. GeForce GTX 460 came to be referred to as the hunter,
incorporating a better balance of speed, efficiency, and cost more
apropos to gamers. Finally, GeForce GTS 450 was dubbed the sniper for
its focus on enabling playable frame rates at 1680x1050, according to
Nvidia.
As silly as that trio of categories seemed, they make it easier for
us to put a finger on the pulse of GeForce GTX 680. Though its name (and
price) suggests a successor to Nvidia’s current single-GPU flagship,
this is decidedly the hunter—a gamer-oriented card that almost
completely de-emphasizes the once-emphatic message of improving
general-purpose compute performance. But hey, it does that whole gamer
thing really well, just like the GeForce GTX 460.
Fitting In Isn’t Always Easy
Regardless of the role it was designed to fill, competition is the
biggest influencer of positioning. AMD may have higher-end cards on its
roadmap that we haven’t seen or heard about yet. However, in the context
of AMD’s six Radeon HD 7000-series boards that are already available,
Nvidia knows exactly what it’s up against.
Had Radeon HD 7970 been 30 or 40 percent faster than it is, there’s a
good chance we wouldn’t be looking at a GeForce GTX 680 today. Maybe it
would have been called GTX 660 or 670. But because of where AMD’s
flagship sits, Nvidia sees justification in crowning its new hunter as a
successor to its old tank—all the while making it pretty clear that
another piece of heavy armor is in the works.
What we have on our hands, then, is a $500 card based on Nvidia’s
GK104 graphics processor, designed specifically for gamers (if you’re
interested in compute potential, you’ll have to keep waiting). GeForce
GTX 680 addresses some of last generation’s most glaring competitive
disadvantages, and it adds a handful of interesting features, too.
Meet GeForce GTX 680
At 10” long, the GeForce GTX 680’s PCB is half an inch longer than
AMD’s Radeon HD 7800 boards and half an inch shorter than the Radeon HD
7900s.
Looking at the card head-on, we see that it employs a centrifugal
fan, which pushes hot air out of the card’s rear bracket. There’s only
about half of one slot available for passing exhaust back there. But as
we’ll see in our thermal and acoustic tests, the GTX 680 does not have a
problem contending with heat.
The rest of the dual-slot bracket plays host to four display outputs:
two dual-link DVI connectors, one full-sized HDMI port, and a
DisplayPort output. All of them are useable concurrently, addressing one
of our sharpest critiques of all prior-gen Fermi-based boards. At long
last, we can consider multi-monitor gaming tests to replace 2560x1600 in
our single-card reviews (and indeed, multi-monitor benchmarks will
follow in a story on which we're already working)! Like AMD, Nvidia
claims that this card support HDMI 1.4a, monitors with 4K horizontal
resolutions, and multi-stream audio.
Up top, GeForce GTX 680 features twin SLI connectors, enabling two-,
three-, and four-way SLI configurations. In comparison, AMD’s Radeon HD
7970 and 7950 similarly support up to four-way arrays.
We also get our first piece of physical evidence that Nvidia’s GK104
processor was designed to be a viable option in more mainstream
environments: GeForce GTX 680 employs two six-pin auxiliary power
connectors. Those two inputs, plus a PCI Express slot, facilitate up to
225 W of power delivery. Nvidia rates this card for up to 195 W.
However, it also says typical power use is closer to 170 W. Keep those
numbers in mind—the available headroom between 170 W and the 225 W
specification ceiling come into play shortly.
Keeping GeForce GTX 680 Cool
Nvidia claims it put a significant effort into three aspects of its
dual-slot cooler’s design, contributing to an impressive acoustic
footprint, even under load. We can peel back the GTX 680’s shroud for a
closer look…
First, the company cites a trio of horseshoe-shaped heat pipes
embedded in the GPU heat sink, which quickly draw heat away from GK104.
Thermal energy is transferred from those pipes into a dual-slot aluminum
sink.
Optimizations to the sink itself also rank on Nvidia’s list of
improvements. For instance, the fin stack is angled where air exits,
creating more space, internally, between the cooler and exhaust grate.
Apparently, in prior designs, heat was getting trapped between the
bracket and fins, affecting cooling performance. This new approach is
said to yield lower temperatures than the older implementation.
Finally, Nvidia says it added acoustic dampening material to the fan
motor—a step it also took with the GeForce GTX 580, which contributed to
getting that card’s noise level down compared to its maligned predecessor.
