Marasmic

please stop. That guy has zero idea of what he is talking about, which has been shown so many times that it isn't even funny. Have you seen his SRH 1540 review? He calls them neutral and boring, their sound signature is very much a U signature, so far from neutral as it can get.
He has also proven that his taste changes from day to day, some days oh I hate treble other days OH YEAH THAT TREBLE.
He is a joke and looked at as a joke by quite a few audio forums, such as head-fi and SBAF.
 

The chip is so small that you cant get the heat out of it efficiently (the main problem with smaller process nodes).  The silicon itself is a thermal insulator at those power densities.
 
The 3600 has more "dark" silicon, thus a lower power density.

Dang.. I thought I was going to win the old video card challenge with my RIVA TNT2 Ultra, but you beat me by a year with that Voodoo.