Rockbox mail archive
Subject: Re: Hard Disk Question
From: Gerald L. Clark (gerald_clark_at_mindspring.com)
Brian Wolven wrote:
> RudiS wrote:
>> Yes in the Atacama desert in a copper mine 4700m above sea level. One
>> other aspect seems to be the cooling. It's maybe ridiculous to think
>> about that for the tiny JB, but our company has installed here several
>> servers from DELL and the most of them got problems with their SCSI
>> hard disks as well. Since we installed an additional air condition in
>> the server cabinet we got rid of that problem finally.
> Hmm, yep, if the cooling depends on moving a certain mass of air past
> a heat exchanger, then the reduced air pressure could put you over the
> threshold where heat buildup becomes a problem. At 4700 m, your
> ambient air pressure is only 51% of that at sea level, assuming a
> scale height of ~7 km for the earth's atmosphere. You need to move air
> *twice* as fast just to achieve the same amount of cooling. Perhaps if
> they overclock the fan motors? =P
> I think they keep airplane cabins at the equivalent of 10,000 ft, or
> just a hair over 3,000 meters. You're 1-1/2 times that... always.
>> But it is an interesting topic, right?
>> Lets see, next monday, when I do my last 10 days period in the mine,
>> I'll test the daily build which was recommended by Linus and further
>> more, I put my Jukebox in cotton wool to reduce the shock waves when I
>> am driving far from paved roads with my 4 x 4 Truck.
> Well, good luck anyway. You probably qualify as the highest Archos
> owner in the world (airline flights excluded) - at least in the
> elevation sense. =)
Hard drives have a maximum altitude rating.
The heads fly above the disc on a thin cushion of air.
Reduce the air density, and the heads crash.
Check the spec sheet for the drive.
Page was last modified "Jan 10 2012" The Rockbox Crew