[Beowulf] Quiet *and* powerful

[Alvin Oga]

hi ya joshua

- what makes noise is typiclly the qualityof the fan, the 
  fan blade design and the size of the air holes and
  distance to the fans

- a fan held up in the open air shold be close to noiseless

- if you want 1U .. you have to put good quality lateral squirrel cages
  far away from everything and still be able to force air
  across the cpu heatsink fins 
	- you should not hear anything

- if you go to 12U or midtower... there is no noise problem
  except for the cheezy "el cheapo" power supply fan 
	( get a good power supply w/ good fan and you wont hear
	( the power supply either

- next choice isto use peltier cooling but you still have to cool
  down the fin on the hot side of the peltier..
	- you can also attach a bracket from teh cpu heatink
	or peltier heatsink to the case ... to get rid of the heat
	assuming the ambient room temp can pull heat off the case

- sounds like your app is based on "quiet operation" and does
  not need to be 1Us ...
	- i'd stack 6 dual-xons mb into one custom chassis and
	it should be quiet as a "nursing room"

== to prove the point ...
	- take all the fans off ( its not needed for this test )

	- take off all the covers to the chassis

	- arrange the motherboards all facing the same way

	- put a giant 12" household fan blowing air across
	the cpu heatink ( air flowing only in 1 direction )
		- preferably side to side in the direction
		of the cpu heatsink fins

	- put a carboard box around the chassis and leave the
	unobstructed air flow of the cardboard opn on the
	cpu side and opposite site
		- put white hospital linen on the box
		that says "do not sit here"

	( probably should do that with the doors locked so
	( that nobody see the cardboard experiment

- after that, you know what your chassis looks like ...
  and still be quiet ..  or you're stuck with 6 mid-tower systems
  vs noisy 1Us
	- 2Us suffer the same noise fate as 1Us ( the way most people
	build it )

- fun stuff .. making the system quiet and run cool ... temperature wise

have fun
alvin

On Fri, 12 Dec 2003, Nicholas Henke wrote:

> On Fri, 2003-12-12 at 12:08, Joshua Baker-LePain wrote:
> > Yes, I know this has been discussed a couple of times, and that my stated 
> > goals are at odds with each other.  But I really need the best bang for 
> > the noise for a system that will reside in the same room with patients 
> > undergoing diagnostic ultrasound scanning.  Our current setup (6 1U dual 
> > 2.4GHz Xeons, with about 11 little fans per node) is ridiculously loud, 
> > and annoys both the patients and the physicians.  This is Bad.
> > 
> > We're willing to pay for better, but don't want to take too much of a 
> > speed hit.  Does anybody have a good vendor for quiet but still high 
> > performing systems?  Is there any hope in the 1U form factor (my Opteron 
> > nodes are somewhat quieter, since they use squirrel cage fans, but are 
> > still too loud), or should I look at, e.g., putting Quad Opterons in a 3 
> > or 4U case?  Or should I look at lashing together some towers (this system 
> > also needs to be somewhat portable)?
> 
> They are not 1U, but the Dell 650N I have is just about silent. At most
> I hear a faint harddrive noise, but most times I hear nothing at all. 
> FYI, this is a dual processor machine as well.
> 
> Nic
> -- 
> Nicholas Henke
> Penguin Herder & Linux Cluster System Programmer
> Liniac Project - Univ. of Pennsylvania
> 
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