Expreview has written one of the first previews of a 55nm GeForce GTX 260 graphics card, they compared the card against its 65nm 216 shader processor brother and the old 65nm card with 192 shader processors. You can check it out over here.
Oddly enough, the card seems to use a bit more power in load and the temperatures are higher than the 65nm predecessor because the new card uses a cheaper cooler:
Because of improvement in processing, 55nm GeForce GTX260 features better overclocking ability. Its core clock is improved by more than 25%, which counts most for high-end players.
With re-designed PCB and shrinked cooler, so the card doesn’t provide lower power consumption and temperature as we expected. Instead, the power consumption (loaded) and temperature show a bit increase compared with GTX260-65nm. But in all benchmarks, 55nm GeForce GTX260 works steadily.
As to 3D performance, 55nm GeForce GTX260 doesn’t bring us any surprise. In most benchmarks, it outperforms Radeon HD4870 1GB. Featuring CUDA and PhysX, GTX 260 offers great performance price benefit.