Energy consumption vs % utilization?

Deepak Jain deepak at
Tue Oct 26 18:24:53 UTC 2004

> Actually I think nobody does calculate "real" utilization,
> as there are a lot of soft factors to be taken into account. 

Electrical usage for a datacenter is pretty consistent throughout a 
month, even as measured by a sum of days. The utilization of the systems 
inside of it are almost anything but consistent... even during boot up 
it would be nearly impossible to determine the instantaneous necessary 
power draw.

Separately, deploying applications to clusters of machines where the 
cluster is dynamically resized [more machines are turned on/off] 
depending on load is a non-trivial function and outside the operational 
experience/need of most customers.

But even assuming you could do that, the best approximation I could 
imagine for an Internet data center would be something akin to its 
network traffic graph [assumption being that network load amongst a 
stable set of customers is proportionate to the processing power 
required to produce it... even if an individual customer uses much more 
CPU power to do that at a specific time quanta]. Basically, if you use 
1Mb/s at noon on Monday, and 1.2Mb/s at noon on Tuesday with the same 
customer set, you can probably estimate that your system's load is 20% 
higher than it was on Monday. Assuming you aren't operating at either 
the very low extreme or very high extreme. At least that would be my 

If all applications were designed to virtualized ala mainframe style, 
this clustering concept might work to dynamically redeploy resources... 
However the mainframes themselves are inherently not-smooth-stepped in 
terms of their power/cpu curves, so its probably a dead issue in that 

Deepak Jain

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