Expreview writes NVIDIA is rolling out 55nm GeForce 9600 GT graphics cards. The naming and even the clockspeeds of the cards remain the same but these 55nm parts should be cheaper to manufacture and might overclock higher than its 65nm predecessor.
Right after 9800GTX+, NVIDIA begin shrinking 9600GT to 55nm. But this time is a bit different, there will not be another plus mark after 9600GT’s name because NVIDIA want more stealth.
The only change of 55nm version is the mark on die. The mark on a 65nm die is G94-300-A1 and 55nm die is G94-300-B1. The clock keeps 650MHz/1625MHz/900MHz (core/shader/mem) so more overclocking headroom can be leave to customers and vendor partners.