rack power question

Frank Bulk - iNAME frnkblk at iname.com
Tue Mar 25 01:26:06 UTC 2008


So perhaps the question isn't so much how many kW's I can pack into a 42U
rack, but for the data center designer, what's the best price point if real
estate is not a significant issue.  Or to say it another way, what kW
density per rack will give me the lowest priced capital and operating cost
per square foot.  Does it really matter if you can only offer 5kW/rack if
you can price it at 80% of the guy who can sells a 10kW/rack product?  Or is
this a tough point for the sales person to make?

Frank

-----Original Message-----
From: owner-nanog at merit.edu [mailto:owner-nanog at merit.edu] On Behalf Of Ben
Butler
Sent: Sunday, March 23, 2008 12:11 PM
To: nanog at merit.edu
Subject: RE: rack power question

There comes a point where you cant physically transfer the energy using air
any more - not less you wana break the laws a physics captin (couldn't
resist sorry) - to your DX system, gas, then water, then in rack (expensive)
cooling, water and CO2.  Sooner or later we will sink the hole room in oil,
much like they use to do with Cray's.

Alternatively we might need to fit the engineers with crampons, climbing
ropes and ice axes to stop them being blown over by the 70 mph winds in your
datacenter as we try to shift the volumes of area necessary to transfer the
energy back to the HVAC for heat pump exchange to remote chillers on the
roof.

In my humble experience, the problems are 1> Heat, 2> Backup UPS, 3> Backup
Generators, 4> LV/HV Supply to building.

While you will be very constrained by 4 in terms of upgrades unless spending
a lot of money to upgrade - the practicalities of 1,2&3 mean that you will
have spent a significant amount of money getting to the point where you need
to worry about 4.

Given you are not worried about 1, I wonder about the scale of the
application or your comprehension of the problem.

The bigger trick is planning for upgrades of a live site where you need to
increase Air con, UPS and Generators.

Economically, that 10,000KW of electricity has to be paid for in addition to
any charge for the rack space.  Plus margined, credit risked and cash
flowed.  The relative charge for the electricity consumption - which has
less about our ability to deliver and cool it in a single rack versus the
cost of having four racks in a 2,500KW datacenter and paying for the same
amount of electric.  Is the racking charge really the significant expense
any more.

For the sake of argument, 4 racks at £2500 pa in a 2500KW datacenter or 1
rack at £10,000 pa in a 10000KW datacenter - which would you rather have?
Is the cost of delivering (and cooling) 10000KW to a rack more or less than
400% of the cost of delivering 2500KW per rack.  I submit that it is more
that 400%.  What about the hardware - per mip / cpu horse power am I paying
more or less in a conventional 1U pizza box format or a high density blade
format - I submit the blades cost more in Capex and there is no opex saving.
What is the point having a high density server solution if I can only half
fill the rack.

I think the problem is people (customers) on the whole don't understand the
problem and they can grasp the concept of paying for physical space, but
cant wrap their heads around the more abstract concept of electricity
consumed by what you put in the space and paying for that to come up with a
TCO for comparisons.  So they simply see the entire hosting bill and
conslude they have to stuff as many processors as possible into the rack
space and if that is a problem is is one for the colo facility to deliver at
the same price.

I do find myself increasingly feeling that the current market direction is
simply stupid and had far to much input from sales and marketing people.

Let alone the question of is the customers business efficient in terms of
the amount of CPU compute power required for their business to generate 1$
of customer sales/revenue.

Just because some colo customers have cr*ppy business models delivering
marginal benefit for very high computer overheads and an inability to pay
for things in a manner that reflects their worth because they are incapable
of extracting the value from them.  Do we really have to drag the entire
industry down to the lowest common denominator of f*ckwit.

Surly we should be asking exactly is driving the demand for high density
computing and in which market sectors and is this actually the best
technical solution to solve them problem.  I don't care if IBM, HP etc etc
want to keep selling new shiny boxes each year because they are telling us
we need them - do we really? ...?

Kind Regards

Ben


-----Original Message-----
From: owner-nanog at merit.edu [mailto:owner-nanog at merit.edu] On Behalf Of
Valdis.Kletnieks at vt.edu
Sent: 23 March 2008 02:34
To: Patrick Giagnocavo
Cc: nanog at nanog.org
Subject: Re: rack power question




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