* Posts by Liam Newcombe

1 publicly visible post • joined 18 Jul 2007

How green is my V-word?

Liam Newcombe

This is rather more to this issue than in this analysis

The BCS Data Centre Specialist Group have been investigating this issue in some depth. The load to power relationship of servers varies greatly, but none are linear. There are many more components than just the processors that vary their power with system load and programs already underway to expand this. We are, however, not likely to see linear either, due to the 'power floor' of components required for the server to be running at all.

There is significant benefit to be had from virtualisation but this, again varies. High overhead virtualisation that invokes a full copy of the operating system for every application, whilst an improvement, is fundamentally limited and does not represent a signficant change in mind set from 'one app per server'. Low overhead virtualisation such as Solaris 10 containers can go much further and provide much more benefit.

The impact on the data centre infrastructure and power bill is also rather more complex, whilst traditional cooling systems will not react much, the power delivery infrastructure will and the impact will be visible on the bill. More modern data centre design approaches will react very differently to this change in load density and profile.

The real savings do come at the data centre level. The hardware cost of the server has been substantially exceeded by the cost of the data centre power infrastructure to support it for several years now, with the power cost expected to exceed the server cost within a couple of years. The price of a server is increasingly irrelevant in the cost of ownership equation.