Advanced Micro Devices, Inc.'s (AMD) Fusion processors may be stealing the spotlight, but AMD is determined to show gamers that it still wants to give them a whole lot of love.  With Radeon 6990 being arguably the king of single-card desktop graphics performance today, AMD has unleashed a powerful mobile GPU that it claims is "the world's fastest notebook GPU."

The chip is named the Radeon HD 6990M and it packs 1120 stream processing units (SPUs) -- up 16.7 percent from the 960 found in AMD's previous top end offering, the Radeon 6970M.  Texture units (56) and the core clock (715 MHz) have also been bumped.  ROPs and memory clock remain the same.  However, in the memory department, the Radeon 6990M packs 2 GB of GDDR5.

The GPU may confuse some in that it's a single-chip (Barts) design, unlike the dual-chip (Cayman Islands) design found in the desktop Radeon 6990.  The chip also contains a mixture of features from the Evergreen and Northern Islands families, meaning that it's not exactly like its desktop 6000 series brethren.

Slides from AMD show the chip outperforming both its own Radeon 6970M and NVIDIA Corp.'s (NVDA) GeForce GTX 580M in games like Batman Arkham Asylum, Dragon Age 2, Shogun 2, BattleForge, Left 4 Dead, Metro2033, Wolfenstein MP, The Chronicles of Riddick, and ET: Quake Wars.  No independent benchmarks have been released yet, so the validity of these claims depends on how much you're willing to trust AMD.

The chip will land as an option for Dell Inc.'s (DELL) Alienware M18x and Clevo's P170HM and P150HM notebooks, both of which also offer the GTX 580M.  

These notebooks may support Crossfire configurations of more than one 6990M.  One 6990M is pretty far from its desktop namesake, but two could offer somewhat closer performance.  A Radeon 6990 has 3072 SPUs, while a pair of 6990Ms would have 2240 SPUs.  Unless you're mining bitcoins or counting framerates, the performance of a pair of 6990Ms and a Radeon 6990 should be virtually identical in current generation PC titles.

AMD has said that the new chip will support Eyefinity, HD3D, and all its other latest and greatest technology.  According to AnandTech, though, the chip will not support switchable graphics (à la NVIDIA's Optimus).  That, says AMD, is currently reserved for lower end CPUs.

The chip is available immediately, and AVADirect is already making the GPU available in its gaming notebooks.  Expect more manufacturers to jump on the AMD bandwagon in the near future.