Measuring real energy consumption (JouleMeter)
Theoretical tables of consumption of a microcomputer, notebook or servers are extensive on the Internet. In general use 4 forms of calculations:
This method is not trusted because it does not have any real basis for the percentage.
This method is accurate calculation but may increase the actual consumption, since it takes into account the maximal value of each component, with your processor consumption varies according to the demand, the disk might disconnect idle, apart from not taking into account USB devices such as keyboard, mouse and pendrive.
However, this method also has the disadvantage of requiring measurement is human and not keep records of swings as the use of components fit demand processing.
For this download JouleMeter free tool created by Microsoft research http://research.microsoft.com/en-us/projects/joulemeter/default.aspx
The CPU and memory consumption for this is very low and will not affect the environment, being allowed to install on VMs based processors with Intel-VT or AMD-V.
Now you can make actual tables of consumption, stations and other servers in your network. Soon I will do a post comparing the consumption of servers viewing the virtualization scenario.