Energy consumption vs % utilization?

Hannigan, Martin hannigan at
Tue Oct 26 18:50:30 UTC 2004

This is far more complicated than this. That's why I suggested 
the Datacenters list.

A lot is determined not just by your revenue target per square foot, 
but cooling, your distribution, your breaker density and sizing, etc.


Martin Hannigan                         (c) 617-388-2663
VeriSign, Inc.                          (w) 703-948-7018
Network Engineer IV                       Operations & Infrastructure
hannigan at

> -----Original Message-----
> From: owner-nanog at [mailto:owner-nanog at]On Behalf Of
> Nils Ketelsen
> Sent: Tuesday, October 26, 2004 2:09 PM
> To: nanog at
> Subject: Re: Energy consumption vs % utilization?
> On Tue, Oct 26, 2004 at 01:52:51PM -0400, Gregory (Grisha) 
> Trubetskoy wrote:
> > Sorry, this is somewhat OT.
> Also Sorry, but I think the question itself is completely flawed.
> > 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?
> What does 98% underutilized mean?
> What is the utilization of a device with fully built out RAM 
> that is used
> to 100%, when the CPU is used 2% only?
> What is the utilization of a system, that uses two percent of the
> memory and two percent of the available CPU time, when the policy
> of the top secret organization owning this system requires, that the
> application is running on a seperated machine?
> Sure many machines might be (computing power wise) able to
> handle Firewalling, Routing, Webserving, Database Serving, 
> Mailserving and
> storing accounting data, but still there might be very good reasons to
> seperate these on different machines.
> If you take points like policy requirement (see above:
> an application might by policy utilize a machine to 100%), 
> different types
> of resources, failover etc. into account, you might end up
> with different numbers then just looking at the CPU (and I
> have the feeling that is what you did or were intending to do).
> Actually I think nobody does calculate "real" utilization,
> as there are a lot of soft factors to be taken into account. 
> Nils

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