The product we’ll be featuring here today, the AMD Radeon HD 6990, should come as no surprise to anyone that even remotely stays on top of the PC graphics scene. News of the Radeon HD 6990’s arrival has been circulating for many months now, although back in the early days it was referred to by its codename—Antilles. Antilles was the codename given to the dual-Cayman GPU powered graphics card that would eventually top AMD’s graphics card line-up and supplant the Radeon HD 5970 that’s served the company so well, since its release way back in November of ’09.
While news of Antilles development wasn’t really news at all, considering AMD’s GPU design philosophy these past few years with the likes of the previous generation Radeon 4870 X2 and Radeon HD 5970, the actual final specifications of the Radeon HD 6990 were unclear for quite some time. Knowing the die size of a Cayman GPU and the power consumption characteristics of a single Radeon HD 6970 that employs one of these chips, some hypothesized (including yours truly) that pairing two of them on a single PCB, along with 4GB of RAM, would be no easy task. Some guessed that the card would have fewer stream processors enabled than a fully-equipped Cayman GPU or perhaps lower clocks than a Radeon HD 6970 and that its specs would place it somewhere in between Radeon HD 6950 and HD 6970 CrossFire configurations. However, it turns out AMD was actually able to cram what is essentially a pair of Radeon HD 6970s onto a single PCB. Sort of.
Take a gander at the specifications below and you’ll notice there’s two configurations of the Radeon HD 6990 listed. Those don’t represent two different cards, though. The Radeon HD 6990 actually sports two different BIOS configurations that can be used with a simple flip of switch. In one configuration, the Radeon HD 6990 falls within expected power limits, but in the other, the card will actually run beyond the PCIe power specs. It’s a pretty wild setup to say the least. You’ll see what we mean as we progress through the pages ahead and reveal all of the juicy details.
A lot of engineering when into designing and building the Radeon HD 6990. So much so that it has spanned a few GPU generations. With that in mind, we’d suggest checking out a few past HotHardware articles to fully grasp everything that the Radeon HD 6990 has going on under its virtual hood. We won’t be rehashing many of the architectural details that have already been covered in previous articles:
- AMD Radeon HD 6970 & 6950 Debut: Enter Cayman
- ATI Radeon HD 5970 Dual-GPU Powerhouse Review
- ATI Radeon HD 4870 X2 - AMD Back On Top
- ATI Catalyst 8.3 Sneak Peek: CrossFireX and More
- ATI Radeon X1950 Pro with Native CrossFire
In our coverage of the Radeon HD 6970 and 6950, we go in-depth regarding the architecture and features of AMD’s Cayman GPU, two of which power the Radeon HD 6990. In our reviews of the Radeon HD 5970 and 4870 X2, we talk of AMD’s GPU design philosophy and how the company has been able to use dual GPUs on a single PCB. And in the Catalyst Sneak Peek and X1950 coverage, we discuss some drive details and native CrossFire implementation. But enough with history, let's look at AMD's new flagship.