Yep, the Radeon HD 6990 is long—just a sliver shy of a full 12", in fact, inviting all sorts of remarks that are surely beneath us. You will want to check the clearance in your case carefully before ordering up one of these puppies. Even the ridiculously lengthy 5970 is a tad shorter.
Beneath the 6990's massive cooling shroud lies a brand-new board design that, interestingly, places a single blower in the center of the card, above the voltage regulators and the PCIe bridge chip that acts as an interconnect between the two GPUs and the rest of the system. Those VRMs, incidentally, are digital programmable units from Volterra that are unique to Antilles. AMD says they enable lower temperatures and lower power draw than conventional VRMs.
The blower is flanked by a pair of heatsinks with copper vapor chambers at their bases. AMD claims that, although this card fits into roughly the same form factor as the 5970, it moves 20% more air with this arrangement. In addition, the firm tell us the thermal interface material between the heatsinks and the GPUs is a special, phase-change variety that offers 8% better performance than the standard gray goo. Take note: if you disassemble your card, you'll likely have to use regular thermal paste when reassembling it, sacrificing some of its cooling efficiency. We've avoided taking ours apart, so far, because we want our power, noise, and temperature readings to track with what you'd see from retail products.
An array of compact Mini-DisplayPort connectors allows the 6990 to sport a rich mix of display outputs while leaving room for a full slot cover of exhaust venting. The 6990, obviously, can drive up to five displays natively. Since it supports DisplayPort 1.2, it can even drive multiple displays simultaneously off of a single output with the help of a DisplayPort hub.
AMD clearly leads the industry on the display output front. The only drawback is the need for adapters to support "legacy" displays with HDMI or DVI inputs. Fortunately, every Radeon HD 6990 will ship with a trio of adapter dongles to convert those Mini-DP ports to serve other standards: one passive HDMI type, one passive single-link DVI type, and one active single-link DVI type. Out of the box, the 6990 should be able to drive a trio of single-link DVI monitors, then. The reason that third adapter is of the "active" variety is that the GPU has a limited number of timing sources for its display outputs. If you'd like to drive more than three "legacy" displays with a 6990, you'll need additional active adapters. Similarly, driving a second or third dual-link DVI display, such as a 30" panel, will require additional active, dual-link-capable dongles.
All of this to-do about multiple display is, of course, only an issue because AMD has been pushing its Eyefinity multi-monitor gaming feature so enthusiastically in the past year and a half—and because the 6990 looks like the perfect device for driving large numbers of megapixels. Given the 6990's five-way output array, AMD has pointed out how naturally this card would support an interesting display configuration: a five-display-wide wall of monitors in portrait orientation. That sounds like a whole lotta bezel area to me, but it's certainly a bevy o' pixels.
Before we move on to our test results, where you can see exactly how the 6990 performs, there's just a couple more details to which we should attend. Although the 6990 is being unveiled today, you likely won't see it selling at online retailers until some time later this week or perhaps early next. When it does arrive, if you'd like to make one your very own, you need only hand over something close to its list price to your favorite online retailer. That price? $699.99.
That's a lot, but given that the Radeon HD 6970 is selling for about 340 bucks a pop, this single card that has essentially two of 'em onboard isn't priced at any great premium, believe it or not.