[Beowulf] Opteron cooling specifications?

[Bruce Allen]

Bill,

I have similar issues in purchasing. U. of Wisconsin requires that we use 
a sealed bid system, so writing good specs is important.

You can get some protection by requiring that in their submisssion a 
bidder provide you with MTBF (Mean Time Between Failure) statistical data 
for ALL fans in a system and for the power supply.  You can also require 
that (example language) 'when system is fully loaded the CPU temperature 
must be at least 10 Celsuis below the CPU manufacturers maximum 
recommended operating temperature'.

Then have your purchasing people add language which allows you to take 
overall system reliability and total cost of ownership into account in 
making a purchase descision (rather than just the contract cost).  This 
allows you to exclude a system if the MTBF numbers are too low.

Cheers,
 	Bruce


On Thu, 27 Apr 2006, Bill Broadley wrote:

>
> I'm writing a spec for future opteron cluster purchases.  The issue of
> airflow came up.
>
> I've seen a surprising variety of configurations, some with a giant rotating
> cylinder (think paddle wheel), most with a variety of 40x28 or 40x56mm
> fans, or horizontal blowers.
>
> Anyone have a fan vendor they prefer?  Ideally well known for making
> fans that last 3+ years when in use 24/7.
>
> A target node CFM for a dual socket dual core opteron?
>
> A target maximum CPU temp?  I assume it's wise to stay well below the
> 70C or so thermal max on most of the dual core Opterons.
>
> Seems like there is a huge variation in the number of fans and total CFM
> from various chassis/node manufacturers.  A single core single socket
> 1u opteron I got from sun has two 40mm x 56mm, and 4 * 40mm x 28mm fans.
> Not bad for a node starting at $750.
>
> Additionally some chassis designs form a fairly decent wall across the
> node for the fans to insure a good front to back airflow.  Others seem
> to place fans willy nilly, I've even seen some that suck air sideways
> across the rear opteron.
>
> In any case, the nature of the campus purchasing process is that we can
> put in any specification, but can't buy from a single vendor, or award
> bids for better engineering.  So basically lowest bid wins that meets
> the spec.  Thus the need for a better spec.
>
> Any feedback appreciated.
>
> -- 
> Bill Broadley
> Computational Science and Engineering
> UC Davis
> _______________________________________________
> Beowulf mailing list, Beowulf at beowulf.org
> To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
>