[103436] in North American Network Operators' Group
Re: cooling door
daemon@ATHENA.MIT.EDU (Matthew Petach)
Sun Mar 30 16:57:36 2008
Date: Sun, 30 Mar 2008 13:55:05 -0700
From: "Matthew Petach" <mpetach@netflight.com>
To: "Alex Pilosov" <alex@pilosoft.com>
Cc: "Paul Vixie" <vixie@isc.org>, nanog@merit.edu
In-Reply-To: <Pine.LNX.4.44.0803291402050.23130-100000@bawx.pilosoft.com>
Errors-To: owner-nanog@merit.edu
On 3/29/08, Alex Pilosov <alex@pilosoft.com> 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.
Matt
