http://www.itjungle.com/big/bigindex.html Description IBM mainframes are the low energy choice, says Big Blue. It likes to pit a mainframe running zLinux intensively on IFL engines against racks of X64 Linux servers that are lightly loaded. IBM's analysis suggests that the mainframe solution can help you slash power and cooling costs. But IBM glosses over the details. In practice, it comes down to cases. Still, it has become easier to get information about your own particular situation and to see how your practices can affect power and cooling requirements. http://www.itjungle.com/big/big082608-story01.html