7600GT / 6600GT Temp

[Bache]

Is a 7600GT cooler than a 6600GT?

If it is, is this due to smaller micron GPU, ram type or both?

 

[NaDa]

http://www.atomicmpc.com.au/forums.asp?s=2&c=7&t=9354

http://www.xbitlabs.com/articles/video/display/power-noise_5.html

http://www.xbitlabs.com/articles/video/display/geforce6600gt-oc_3.html

These links should answer your first question.
About the second question. Probably GPU shrink, but who cares?