It has more copper layers and run colder:
http://www4.tomshardware.com/cpu/02q3/020821/index.html
http://www.anandtech.com/cpu/showdoc.html?i=1685
Also some rumours that AMD will use SOI with Barton.
http://www4.tomshardware.com/cpu/02q3/020821/index.html
http://www.anandtech.com/cpu/showdoc.html?i=1685
Also some rumours that AMD will use SOI with Barton.