On March 8th, 2011, AMD unloaded both barrels on the ultra-enthusiast performance graphics card market, with the spec-busting, power-supply wilting, dual GPU Crossfire-on-a-stick AMD Radeon HD 6990 graphics card - the fastest graphics card on the planet. Depending on who you talk to, it takes that title from either the 4 month old NVIDIA GeForce GTX 580 or its predecessor, the AMD ATI Radeon HD 5970 launched 15 months ago.

The AMD Radeon HD 6990, codenamed Antilles in the Northern Islands product map, is the most recent pinnacle of AMD's sweet spot strategy that was adopted in 2006. A refocus from building the single most high powered GPU each generation, AMD instead decided to build a great performance part that, as a single GPU product, sits at a more accessible price point. To compete in the highest echelons, in the rarefied air of the $500+ stratosphere for Ultra Enthusiast products, the high end part would feature two GPUs on a single board - CrossfireX on a stick.

The AMD Radeon HD 6990 features two Cayman XT cores, 2GB of GDDR5 per GPU, and a split personality. Buying the AMD Radeon HD 6990 you get two cards in one - a stock clocked Gary Busey level crazy card but, flip the dual BIOS switch, and you're in the town where Charlie Sheen is Mayor. Below you'll see this dual fire breather' specifications, which arrived to us in this snazzy Dragon Age briefcase.

Specifications

• $699USD SEP

• Dual 40nm Cayman XT low-leakage GPUs

• 830MHz Core Clock

• 1536 STREAM cores per GPU (VLIW-4)

• Vapor Chamber heatsink per GPU

• 2GB GDDR5 per GPU

• 1250MHz Memory Clock (5Gbps QDR)

• 256-bit Memory Interface per GPU

• Power:

• 37W Idle

• AMD Powertune limited 375W Max Board Power

• 350W Estimated Average Gaming Power

• Supports AMD Eyefinity, Eyespeed, AMD HD3D

• Dual-Link DVI + 4x mini-DisplayPort outputs [Native Eyefinity 5x1 support]

• Bundled Adapters:

• mini-DP to HDMI 1.4a

• mini-DP to SL-DVI

• Active mini-DP to DVI for 3 'legacy' displays in Eyefinity

• Dual Slot 12" form factor with dual 8-pin PCI-Express Power Connectors

• Dual BIOS for OC Mode:

  • Increased GPU core voltage

  • Increased GPU core clock: 880MHz

  • Increased AMD PowerTune limit: 450W

• Single AMD CrossfireX connector supports AMD Radeon HD 6900 series for Tri/QuadFire

Part I of our AMD Radeon HD 6990 coverage will dig into the design, features and 1080p performance of the HD 6990 against a selection of its competitors. We'll also take a look through the new features of project Mjolnir, stage 1 of which is the upcoming AMD Catalyst 11.4.