[eldavido]

My experience was a little different.

Power is the dominant cost in datacenters unless you have very, very expensive switches. Power drives direct electricity consumption, the need for backup batteries and UPSes, cooling, and fans.

You can get pretty high-powered supermicro machines for only like 1000 or 2000 dollars these days. Over 5 years, that works out to only $16/month.

A 42U cabinet from HE (Hurricane Electric) that's "on sale" (http://he.net/colocation.html) runs $400/month. You need 20-30 servers before the spend on machines starts to overtake power. And I honestly doubt you'd be able to put 30 machines in that cabinet before hitting their power ceiling. I walked through an Equinix facility a while ago and if you hit 10KW/rack that's considered "hot". It's not hard to do if you stuff an entire 42U rack with 1U multi-core machines that each have CPUs drawing 50-100 watts/core (not unlikely with high-end Xeons). 15KW/rack is really hot.