If you want a really energy efficient setup then why not go for a single 65W quad core Phenom rather than two dual core Opterons? The question might be a little hypothetical considering the 9150e hasn't been released yet, but it is only a matter of months now (I hope). Any thoughts on how the two would compare performance wise?

It is amazing that AMD still seem to have the edge in performance per Watt. It is a shame they are still on a .65 process, their current chips on a .45 process would be truly phenomenal.

Jim