Servers, switches and routers certainly suck up a lot of electricity. But according to power engineers at Cleveland-based Eaton Corp., all that hardware actually accounts for less than a third of your data center's electricity demand. Your HVAC and power management systems gobble up the rest.

So, if you want to go green, more-efficient computer and network systems aren't enough.

One place to start is with your uninterruptible power supply, says Pedro Robredo, product line manager at Eaton's power quality division. He says the company's transformerless UPS 9395 825 kVA is more efficient because transformers squander kilowatts and take up a lot of real estate.

Fred Miller, another Eaton product line manager, says combining the UPS 9395 825 and its power distribution unit, which handles power loads for each rack of servers, can get you to 98.5% power efficiency.

Pricing is implementation-specific.

An Engine for Ruby

The hottest thing in software development? It's not Web services. It's not.Net. It's Ruby on Rails.

Ruby is the open-source programming language, Rails is the Ruby-built open-source development framework. Combined, they make the most efficient development environment available, advocates assert. And it's hot enough for a Web hosting company to be dedicated to running applications built with it.

Engine Yard Inc. has a staff of 75 to run two data centers in North America hosting Ruby on Rails apps; another is being built in London. According to Lance Walley, CEO of the two-year-old start-up, developers are flocking to Ruby on Rails because it would take them more time to write apps in Java or.Net.

But why do Ruby on Rails applications deserve a special hosting operation? Alas, Ruby has some deficiencies, Walley says. For example, it doesn't use computing resources as efficiently as other languages, so scaling apps can be a problem. But, he says, his data center crews are experts at scaling Ruby apps. Engine Yard specialists also know how to test the stability of Ruby on Rails apps with existing open-source tools. Their knowledge of the development environment can be critical, Walley says, because Ruby on Rails is poorly documented in many areas, such as interacting with apps written in Java or.Net.

A "slice" (CPU, memory, storage and such) of San Francisco-based Engine Yard's data center starts at $399 per month.

For more enterprise computing news, visit Computerworld. Story copyright Computerworld, Inc.