AMD has finally gone and put out a dual GPU solution of their latest architecture. The AMD Radeon HD 6990
has two Cayman XT ASICS on board with a core clock speed of 830MHz. Holding a whopping 4GB of DDR5 ram with 3072 stream processors and 64 texture units, the AMD Radeon HD 6990 can put out 5.1 TFLOPS of computing awesomeness. All this comes at a price though and that would be a $699 price tag. Fitting considering that it's a Radeon 6990.
Enthusiasts will like the dual-bios switch that was released in AMD's previous card. Here, you can set the card to overdrive which increases the clock speed to 880MHz and voltage up to 1.175V from 1.12V. You'll be able to push your card further from the default settings, but you'll need to give it more power. The overdrive limits have been pushed here to 1.2GHz and 6GBs memory speed as well.
You can drive up to six different displays off this one card. The bracket features ones DL-DVI connector and 4 DisplayPorts with compatibility for version 1.2. A new 5x1 portrait mode is being introduced with the drivers that are supporting the 6990. If you don't have DisplayPort capable monitors, the card will come with three adapters so you can get an Eyefinity setup of 3 displays if you want. The adapters are a miniDP to SL-DVI Passive, a miniDP to SL-DVI Active, and a miniDP to HDMI Passive.
The card has a typical load power of 375W but is capable of drawing 450W and you'll need two 8-pin connectors to power the card.
For the card to be able to draw 450W, the team at AMD had to put a little more thought into designing the board. On-board are new-generation digital programmable Volterra regulators for increased current capacity and lower power draw thus reducing the temperatures it can output. A symmetrical layout puts the regulator in the center with the GPUs on either side. This design helps provide efficient power delivery to each GPU. The board is fully enclosed and AMD has used a new thermal interface material that has an 8% improvement over typical TIMs. With that said, AMD doesn't recommend you pulling the board apart to take a look as doing so will compromise the cooling solution and you won't be able to reproduce the efficiency of the cooling using your own thermal paste.
Size wise, the card is the same size as the 5970, but AMD was able to get 20% more air flow through the 6990 due to the new fan and design.
So if you got the cash and want the fastest video card on the planet right now, look no further than the AMD Radeon 6990. Now we have to wait and see if NVIDIA has something out their sleeves to counter AMD's monster of a video card.