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Specs like EyeMasters

GPU
base
clock
(MHz)
GPU
boost
clock
(MHz)
Shader
ALUs
Textures
filtered/
clock
ROP
pixels/
clock
Memory
transfer
rate
Memory
interface
width
(bits)
Peak
power
draw
GeForce GTX 680 1006 1058 1536 128 32 6 GT/s 256 195W
GeForce GTX 690 915 1019 3072 256 64 6 GT/s 2 x 256 300W

The GeForce GTX 690's specifications are eye-popping, which is mostly what you'd expect from an SLI-on-a-stick graphics card. All of the GK104's units are enabled, so many of the key rates are twice the GTX 680's. Since the GTX 690 is a dual-GPU pairing, of course, the peak graphics rates shown in the table above are somewhat less connected to reality than usual. Applications may or may not take advantage of all of that power depending on many things, some of which we'll discuss shortly.

The GTX 690 does have loads of bandwidth on tap, though. Between the two GPUs is a PCI Express bridge chip supplied by PLX; it has 48 lanes of PCIe Gen3 connectivity, 16 lanes routed to each GPU and 16 lanes connected to the host system.

Although the prior-generation GeForce GTX 590 performed more like a couple of down-spec GTX 570s, Nvidia has been able to reach relatively higher with this new card. Some of the credit goes to the Kepler generation's new GPU Boost dynamic voltage and frequency scaling feature, which raises clock speeds to take advantage of any available thermal headroom. The GTX 690's "base" clock is lower than the GTX 680's by quite a bit, but the 690 has more range built into it. The 690's "boost" clock of 1019MHz isn't far from the GTX 680's boost clock of 1058MHz. If the workload and the ambient conditions allow enough headroom, the GTX 690 should operate at something close to its boost clock rate—sometimes at even higher frequencies than that. As a result, Nvidia expects the GTX 690 to perform very similarly to a pair of GTX 680s in SLI.

That's pretty impressive in the grand scheme, since the GTX 680 can claim to be the world's fastest GPU. However, the GK104 graphics processor isn't exactly a heavyweight, by most other standards; it's a mid-sized chip with a modest power envelope and a 256-bit memory interface. In many ways, the GK104 is more like the GF104 chip that powers the GeForce GTX 560 Ti than it is like the GF110 chip that powers the GTX 580. That lineage is probably why the GTX 690 has "only" 2GB of memory per GPU—4GB in total, but effectively 2GB for all intents. (The Radeon HD 7970, by contrast, has 3GB for a single GPU.) The GK104's middleweight status was no doubt helpful when Nvidia was attempting to cram two GPUs onto a single card in a reasonable power envelope. In fact, the GTX 690's max power rating of 300W is 65W lower than the GTX 590's.


The GeForce GTX 590 (left) versus the GTX 690 (right)

In many other respects, the GTX 690 mirrors its predecessor. The board is 11" long, occupies two expansion slots, and requires a pair of 8-pin aux power inputs. The display outputs include a trio of dual-link DVI ports and a single mini-DisplayPort connector. The GTX 590 is just very, uh, plasticky by comparison.

Peak pixel
fill rate
(Gpixels/s)
Peak bilinear
texel filtering
rate int/FP16
(Gtexels/s)
Peak shader
arithmetic
(TFLOPS)
Peak
rasterization
rate
(Gtris/s)
Peak
memory
bandwidth
(GB/s)
GeForce GTX 580 37 49/49 1.6 3.1 192
GeForce GTX 680 34 135/135 3.3 4.2 192
GeForce GTX 590 58 78/78 2.5 4.9 328
GeForce GTX 690 65 261/261 6.5 8.2 384
Radeon HD 7970 30 118/59 3.8 1.9 264
Radeon HD 6990 53 159/80 5.1 3.3 320
Radeon HD 6990 AUSUM 56 169/85 5.4 3.5 320

The GTX 590 is also quite a bit slower than the 690, in theory, as is nearly every other video card out there. Only the Radeon HD 6990 with its special "AUSUM" overclocking switch thrown really competes on any of the key rates, like memory bandwidth and texture filtering—and in other important respects, it's not even close. We're not likely to see a true competitor for the GTX 690 until AMD takes the wraps off of its dual-Tahiti card. Frankly, we're kind of surprised to have made it this far into 2012 without seeing AMD's dual-GPU entry for this generation, since they've been talking about it for some time. Until that product arrives, the GTX 690 is pretty much in a class by itself.

That brings us, inevitably, to the question of price. Given the GTX 690's premium materials and performance, Nvidia has decided to slap a price tag on this puppy that reads: $999.99, one penny short of a grand. I believe that makes the GTX 690 the most expensive consumer graphics card ever. The one-grand sticker essentially doubles the GTX 680's list price, so it makes a sort of sense. Still, you'd kind of hope for some sort of volume discount when buying two GPUs together, wouldn't you?

I dunno. I'm not sure the folks who would pony up for this sort of card will care that much.

One thing that this, er, formidable price tag could do is keep demand in line with the limited supply of these cards. Most folks are keenly aware that the supply of GK104 chips is rather tight right now, since the GTX 680 is tough to find in stock anywhere. Furthermore, the dual-GPU cards of the last generation, the Radeon HD 6990 and the GeForce GTX 590, seem to have been in short supply throughout their model runs. We expect the GTX 690 to reach online store shelves this week, but we have few illusions about them being plentiful, at least initially.