[LINK] Data centre power consumption

[Glen Turner]

Hi Martin,


> Does anyone have power consumption figures for tier II or tier III data
> centres?

I'm not actually sure what they are, and I've bought a lot of space
in my time.

> I seek average wattage per square metre consumption figures.

Traditionally, each customer is allocated redundant feeds of 2500KVA
per 19 inch rack. Obviously with that much power in, you need that
much cooling (which consumes about 30% more power if you are tracking
this from a greenhouse budget point of view).

The problem here is that demand has well outstripped the traditional
parameters.  People want racks which are 1200mm deep rather than 600mm.
That obviously means an increasing in row spacing too (so you can get
something 1200 deep into that 1200 rack).

Routers use about half a rack and 7000W. Blade servers are even worse.
That is, a rack with 2500KVA is 5-10 times underpowered for the worst
case.  So if you are constructing a data centre today there's no way
that you'd use the current industry average as a guide to the future.
You just won't be able to sell that space.

This increasing "power density" of modern equipment is a major challenge
for data centre design.  So much so that some data centres in the USA
have a waiting list for power, with requests examined for reasonablness.

I've also seen lots of circumstances where customers have purchased
two racks and left one empty, just to get the power (and its related
aircon) allocation.

Also, the move to caged areas is also leading to a bit of a re-think.
There usually aren't that many really high density power consuming
items. So supplying a cage rather than a rack prevents over-engineering
of power systems.

> Possibly even compared against a price per square metre fro the same
> data centre.

The price per square metre is an odd concept, as there's a lot of
irrelevant space. Consider that walkways, generators, aircon plant
take up most of the space. The figure of interest is the working
space -- which is expressed in racks.

Give me a call if you want - 08 8303 3936 business hours.

-- 
 Glen Turner