From chaos comes order

Put down the flaming torches and pitchforks...

I have been thinking quite a bit about data center environments lately. Seems
only fitting as I am one of the people working on the buildouts for our
Santa Clara, CA. campus to hold the systems (current and next
generation) coming from our now sold, Newark, CA. campus. I keep having
the same thought occur over and over in my head. The real nightmarish
part is the thought that follows it. A vast throng of data center IT
folks chasing me with flaming torches and pitchforks, out to kill the
demon they didn't even want to know existed. (OK...so I was a pretty big
fan of Boris Karloff movies growing up. )


Before I go on, I need you to put the pitchforks down and extinguish the torches....no seriously...put the pitchforks down.


OK. Everybody take a deep breath.


Raised floor is dead!!


Yep, I said it. Raised floor is past its prime. A dinosaur, who's only
future is to become a fossil. It is a 14.4 modem in the land of 3G and
802.11n. Raised floor is dead!!


So why is raised floor dead?


It comes down to higher power density systems, airflow and the efficient
use of space. Did you know that a rack (42U) full of 1U x64 servers
(pick your vendor of choice) will be in the range of 20KW a rack.


Truth be told, you are hard pressed to cool a 10KW rack just with raised
floor air. It can be done. But, 10KW per rack is about the realistic max
for row full of racks. Now you could more easily cool 10KW a rack if you
don't want rows of racks. Take a 10KW rack and put 10-15 foot of "white
space" all around it, it becomes easier to cool. But, guess what? That
"easier cooling" doesn't have much to do with the where the air is
coming from. It has to do with having a bunch of space for that hot air
to dissipate.


OK, if raised floor is dead, how are we gonna cool racks. The answer is
point cooling. A device that delivers the the volume of cold air a
machine needs and extracts the hot air that the machine generates.
Virtually all of these point cooling systems do this by either being
suspended above the rack or attach themselves on to the side of the
rack. And, in the case of phase change systems, to the back of the rack.


There is also another consideration, and it is probably the most
important. Its cheaper. Raised floors are expensive, for both parts and
installation. The installed cost of raised floor is in the $50 to $75 a
sqft. And point systems are usually cheaper per KW of cooling. Some ball
park numbers, from a source I cannot name, work out the the installed
cost of traditional raised floor CRAC unit cooling system to be in the
range of $1500 per KW of cooling. A point cooling system works out to
about $1000 per KW of cooling.


So lets do a little math. Say you have a 2500 sqft data and you are
going to put 80 20KW racks in it.


The raised floor is going to cost about $60 a sqft or $150K  (60 * 2500
= 150000)
CRAC HVAC is $1500 per KW or $2.4 million  (80 * 20 * 1500 = 2400000)


Point cooling is $1000 per KW or $1.64 million (80 * 20 *1000 = 1640000)


So the raised floor option is approx $2.55 million.


$2.55 million - $1.64 million = $910K


Between a much more effective and efficient cooling model and a savings
of $910K worth of cash, I have to say "raised floor is dead!!"


I guess I shouldn't be that concerned with the flaming torches and
pitchforks, after all, I can buy some really good body armor and bunch of
fire extinguishers with  $940K.

Posted at 02:52PM Feb 08, 2007 by rdsesq in Sun  |  Comments[1]