nanog mailing list archives

RE: Google's PUE


From: Alex Rubenstein <alex () corp nac net>
Date: Wed, 1 Oct 2008 18:22:19 -0400

Google not counting electricity losses from power cords etc gives the
image that it doesn't really want to account everything and want to
skew the numbers as much as possible.

I don't agree with this.

It is commonly accepted that when computing DCIE/PUE, the point of "demarcation" (used that term for the telco crowd) 
is the receptacle. If they did not include losses in transformation, UPS, distribution, etc., then I would agree. But 
they seem clear about that in the discussion.

I would be far more interested in a metric that shows the amount of
power used for each MIPS of CPU power (or whatever CPU horsepower
metric other than clock speed). And also amount of power used for each gbps of
telecom capacity USED.

Another metric would be how much power is used to store how many
terabytes of data on disk. Disks consume much power too.

I think you mean "energy", not telecom. While what you ask for is very important, that is generally a function of 
efficiency of a piece of equipment closed to the consumer. In other words, how efficient a Dell is vs. a HP or 
something. These things do not relate to the definition of PUE/DCIE.


To me, it seems that PUE is just a metric of how efficient the air
conditioning is. 

This is the point. It's a metric of the FACILITY, not the COMPUTATION.




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