A couple of weeks ago, NVIDIA released the GeForce GTX 580M laptop GPU, claiming it was the fastest graphics chip on the market. AMD has just unveiled a quick response, in the form of its Radeon HD 6990M GPU for laptops. The new graphics chip outpaces "any other announced notebook enthusiast GPU" by 25 percent, according to the Sunnyvale-based chipmaker.

AMD says the Radeon HD 6990M was able to outpace the NVIDIA GTX 580 when running such games as Dragon Age 2, Total War: Shogun 2, Alien vs. Predator, Batman: Arkham Asylum, ET: Quake Wars, or Just Cause 2, all in 1080p resolution. The difference varied from 10.36 percent to 25.82 percent.

The newest arrival in the Radeon family is DirectX 11-enabled and works in the CrossFireX mode, combining the power of two AMD GPUs in a single laptop. The Radeon HD 6990M features AMD HD3D technology, which offers stereoscopic 3D gaming and videos (requiring glasses), as well as GPU app acceleration. AMD's Eyefinity multi-display technology is also on board, which supports up to six simultaneous displays.

The new GPU features 1,120 stream processing units, 56 texture units, 128 Z/Stencil units, 32 Color ROP units and up to 2GB GDDR5 900MHz memory, working with a 256-bit interface. The Radeon HD 6990M delivers raw processing power of up to 1.6 teraFlops (1.6 trillion floating point operations per second). External displays and other devices are connected via Dual-link DVI with HDCP, DisplayPort 1.2, HDMI 1.4a or a VGA port.

Dell's Alienware M18x is one of the first laptops to offer the AMD Radeon HD 6990M (also as a pair of GPUs, working in CrossFireX mode). Other laptop brands to feature the new GPU from AMD include Clevo (X7200, P170HM, P150HM) and Eurocom.