For the past six months NVIDIAs been racing to shrink their entire GPU lineup to 55-nm. With the company currently embroiled in a price war with ATI, shrinking their graphics lineup from 65-nm to 55-nm is extremely important to improving the companys bottom line. The smaller process benefits NVIDIA by reducing their manufacturing costs, while consumers also benefit thanks to reduced power consumption (and thus heat output). In theory, this also opens the door to improved overclocking chances as well, although in the case of TSMCs 55-nm process, many of the high performance features found at 65-nm are removed in order to minimize costs.

In any case, shifting GPU production from 65-nm to 55-nm is a win-win for NVIDIA and the consumer.

Nowhere is this more imperative than at the high-end segment of the graphics market. NVIDIAs GT200 GPU is a massive chip with 1.4 billion transistors and a 576mm^2 die size. In fact, some reports have suggested the manufacturing cost for NVIDIA is over $100 per GT200 die alone. With GeForce GTX 260 prices falling from $400 at launch to nearly $200 today, getting these costs down is obviously important.

http://www.firingsquad.com/hardware/NVIDIA_geforce_gtx_295_early_performance/