Why do I buy the 9400gt chip technology is 65nm?

Why do I buy the 9400gt chip technology is 65nm, it also shows that the frequency for GPU550, mempry600, shader1375?
On-line information and different ah???
Heard 9400gt is only one of the technology is 55!
this matter in the end is how

9400GT is the 55nm, you use the software to see what's with GPU -Z Bar

G96 core? G96 is the 9500GT ah, 9400GT is the G86 version GPUZ number ????
, and other software updates that you do not mistake this strange 9800GT show ID device does not show the normal process Have normal