"Green IT" has recently received a lot of attention, especially now that folks in the United States are seeing energy prices that are similar to those that some parts of the world, such as Western Europe, have dealt with for years. But as we investigate "green" further, we find that there are many shades of green.

Of course, “Green IT” usually has the implicit meaning of energy efficiency of IT equipment of various types. In this context, one of the key questions is the power consumption of the devices themselves. For an example of how this is addressed, we’ll refer you to the paper, “Ethernet Power Study of Cisco and Competitive Products”.

As noted in this paper, “Every Ethernet switch requires electricity to function. Efficiency is the measure of power relative to amount of work performed. When products use more power to perform the same amount of work, they are by definition less efficient. Low efficiency creates increased costs for a customer.” Consequently, the method used in this paper for comparison is simply to measure the power consumed and the cost of that power. And another key component to the calculation is the heat produced by the equipment. The less efficient the equipment is, the more heat is generated, and the more air conditioning is needed. Consequently, this power should be considered as well.

This is, by the way, in rather stark contrast to Steve’s early days in computing. At that time, in the early 1980s, there were still two old IBM 360 computers that were used for backup in the computer center where he worked. It was often noted, with a degree of truth, that these water-cooled systems were only fired up whenever we needed extra heat in the winter.

We’ve come a long way since then, and in the next newsletter we’ll continue to consider aspects of being green.

Steve Taylor is president of Distributed Networking Associates and publisher/editor-in-chief of Webtorials. Jim Metzler is vice president of Ashton, Metzler & Associates.