ATI is revamping its Mobility Radeon laptop-friendly graphics chip line-up not only with a pair of mid-range parts offering better performance per watt, the company claimed, but also the GPU fabbed using strained silicon technology: the gamer-oriented Mobility Radeon X1700.

Nvidia launched the world's first 80nm mobile GPU earlier this month, and the strained silicon announcement is ATI's attempt to get one up on its arch-rival. Strained silicon is the process by which the lattice of silicon atoms in a semiconductor are pulled further apart than usual in order to improve the flow of electrons between them. Intel has been using the technique for some time. AMD introduced it in its 90nm process.

AMD's version, for example, uses Silicon-Germanium (SiGe) to stretch a layer of pure silicon. The SiGe atoms are further apart than the silicon's, which move to align themselves with the SiGe lattice. Once the silicon lattice has been stretched, the SiGe layer is removed. It's not known what stretching material TSMC uses, but the effect is the same: "dramatically improved performance per watt", according to ATI.

ATI's own figures show the X1700 doesn't yield radically better 3DMark and games benchmarks than the X1600, but the point is it delivers the extra performance without a comparable increase in power consumption.

The Mobility Radeon X1700 is, nonetheless, a 90nm chip. It's got 12 pixel shader processors in three groups of four, all fed by a quintet of vertex processors. The part uses ATI's already-launched PowerPlay 6.0 power management system, and incorporates the company's Avivo video processing system complete with Blu-ray Disc and HD DVD video decoding.

ATI also plans to upgrade its Mobility Radeon X1300 and X1400 to the X1350 and X1450, respectively. Both part are pitched at mainstream notebooks and deliver better performance per Watt ratings than their predecessors, though ATI didn't provide an exact comparison.

All three GPUs are designed to enhance ATI's sales pitch to laptop makers who might otherwise be considering an integrated graphics engine. ATI is also banking on the graphics horsepower required by Windows Vista, DirectX 10, HD DVD and Blu-ray Disc playback to boost demand for discrete notebook GPUs. The company cited an IDC forecast of an upswing in sales of such parts, reversing the decline seen over the past four years. ®