[Beowulf] Re: Reliable CPU fans

[Alvin Oga]

hi ya richard

On Tue, May 11, 2004 at 04:00:55PM -0700, Richard Fryer wrote:
> I have had a fair amount of maintenance on a fairly small cluster (~16nodes)
> with Cooler Master fans.

are we talking about midtower cases or 1Us .. 2Us ... it makes a difference

if midtower, etc, i guess we'd be using the default fans that comes with the cpu

if 1Us .. than we have some issues

> In various workstations I've tried getting Alpha and other brand coolers but
> the real reliability issue has been of course the fans.  When specified I've
> always chosen a ball bearing (some say 'dual' ball bearing) fans, but this
> has not led to spectacular reliability either.
 
alpha is a heatsink manufacturer

heatsinks and fans ...
	http://www.linux-1u.net/HeatSinkFans/

> Thermaltake seems to be the best I've used but lacking hours-on data for the
> workstations, I doubt the data to be significant.
 
thermaltake fans ( any 1U model ) has been the worst fan for us

we usually get vantec p4 fans for 1U
sometimes we get the coolermaster ones

specific models .. depends on the month ... each time is different
as models keep changing and whats in stock at the distributors 
	- we'll try most of um ... but ... thermaltakes was the 
	ones we throw away the most ... the fan on it is worthless
	and if you watch the fan rpm ... its bad ... stops and goes
	even though its supposed to be running at full rpm 

to see which fans NOT to use ....
	- to to the local colo and see if you can see dead fan labels
	and do NOT buy those ...

> Has anyone discovered a good resource regarding CPU cooler reliability to
> point me to?  Or - taken enough data to have a good opinion?

we use indek fans for chassis cooling  and cpu cooling
when we only have a passive heatsink on the cpu ... 
	and not many people carry sanyo/nmb fans ... indek is as good

	- the other problem is most fan manufacturers  do not give us
	any usable MTBF 

we also use about 4-6 fans per cpu(1U box) .... including one for cooling each disk
	- fans are right next to the cpu on the side of the mb

the fan above the cpu that is almost flush to the 1U cover is worthless fan
as one needs say 0.5" - 1.0" of air gap for the fans blades to do its job
and the air that blows on top of the cpu doesnt  bend at 90degrees when it
hits the cpu ( bottom of the heatsink )

we do custom cooling  as needed to get the cpu temp as low as possible

c ya
alvin