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Re: cooling door

  • From: Deepak Jain
  • Date: Mon Mar 31 16:08:50 2008



Matthew Petach wrote:
On 3/29/08, Alex Pilosov <[email protected]> wrote: 
Can someone please, pretty please with sugar on top, explain the point
 behind high power density?

 Raw real estate is cheap (basically, nearly free). Increasing power
 density per sqft will *not* decrease cost, beyond 100W/sqft, the real
 estate costs are a tiny portion of total cost. Moving enough air to cool
 400 (or, in your case, 2000) watts per square foot is *hard*.

 I've started to recently price things as "cost per square amp". (That is,
 1A power, conditioned, delivered to the customer rack and cooled). Space
 is really irrelevant - to me, as colo provider, whether I have 100A going
 into a single rack or 5 racks, is irrelevant. In fact, my *costs*
 (including real estate) are likely to be lower when the load is spread
 over 5 racks. Similarly, to a customer, all they care about is getting
 their gear online, and can care less whether it needs to be in 1 rack or
 in 5 racks.

To rephrase vijay, "what is the problem being solved"? 

I have not yet found a way to split the ~10kw power/cooling
demand of a T1600 across 5 racks.  Yes, when I want to put
a pair of them into an exchange point, I can lease 10 racks,
put T1600s in two of them, and leave the other 8 empty; but
that hasn't helped either me the customer or the exchange
point provider; they've had to burn more real estate for empty
racks that can never be filled, I'm paying for floor space in my
cage that I'm probably going to end up using for storage rather
than just have it go to waste, and we still have the problem of
two very hot spots that need relatively 'point' cooling solutions.

There are very specific cases where high density power and
cooling cannot simply be spread out over more space; thus,
research into areas like this is still very valuable.



The problem with "point" heating is often that the hot point is then the *intake* for other equipment. If you spread your two T1600s into 10 racks (i.e. skip 2, drop one, skip 4, drop 1, leaving two at the end) your hot point problem is much less of a concern.

If you bought 10 racks... not in a row, but SURROUNDING (in each of the rows opposite the cabinets)... Say 12 (a = vacant, b,c = T1600)

aaaa
abca
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You would be doing everyone in your datacenter a service by a) not thinking linearly and b) providing adequate sq ft space to dissipate your heat.

Deepak