Energy consumption vs % utilization?

Tue Oct 26 20:19:06 UTC 2004

Alex Rubenstein wrote:

>
>> I'm looking for information on energy consumption vs percent 
>> utilization. In other words if your datacenter consumes 720 MWh per 
>> month, yet on average your servers are 98% underutilized, you are 
>> wasting a lot of energy (a hot topic these days). Does anyone here 
>> have any real data on this?
>
>
> I've never done a study on power used vs. CPU utilization, but my 
> guess is that the heat generated from a PC remains fairly constant -- 
> in the grand scheme of things -- no matter what your utilization is.

You should be able to pick up simple current / wattage meter from local 
hardware store for $20 or so. That will tell you that on a modern 
dual-CPU machine the power consumption at idle CPU is about 60% of peak. 
The rest is consumed by drives, fans, RAM, etc. As wattage the 
difference is 100-120W (50-60W per cpu)

All modern operating systems do moderate job of saving CPU wattage when 
they are idle (BSD's, Linux, MACOS X, WinXP, etc.)

Pete