CPU temps

[Steve Jardine]

Two type of impeller fans that I am aware of - friction and bearing. Cheap fans (6$ at Frys) are crush type. They have no bearing - they slip the shaft against a sleve with some grease. The whole area is then sealed in to keep grease from going away.

Better type is a decent sealed bearing type. More expensive, but will last longer and can have more pitch to the blade for more movement of air. Make only a little more noise.

Has anyone uses a Peltier cooler? I have seen them in portable coolers for cars, but they seem terribly inefficient.

Seriously, one of the biggest things I have seen that causes heat issues is case design. I find heat kinda fluid like. Takes more energy to go around things. Look at the design of, say a Dell Optiplex. They have plastic conduits to direct the air over critical components (CPU, memory).

I find the HP J servers the coolest in fan design! They have the CPUs with about a 4 inch tall round heat sinks on them. This think has hundreds of fims on it, horizintal slots about 1/8th turn long, and the horizontal layers rotate about a 1/4 turn each layer. The fan is quiet, but moves a ton of air. The air directly leaves the case. Each "module" (memory, plugin board area, drives) has their own fan subsystem. Good design - expensive to make though. Plus, the systems are designed to run in a room at 60 F. 

Want to run 6 hard drives? Better move air over them, especially if they are IDE or derivitive. Over clock the CPU? Think air from outsinde the case over it being better. Fast RAM? put it as low as possible in the case and have the fresh air intake directly in front of it. 

My $0.02 worth as someone used to say...


    Steve

On Sun, 9 Mar 2008 09:43:59 -0400
"David A. Bandel" <david.bandel at gmail.com> wrote:


> Well, personally, and not being a physicist but knowing enough to be
> dangerous (literally), I find fans lacking.
> 
> Primarily, fans (or those I am aware of) use old technology.  They
> have shafts with bearings that are prone to wear and failure (friction
> just rubs me the wrong way ;-) ).  If I were concerned about cooling,
> I'd try to find fans (if they exist) that are maglev based -- that is,
> the impellor shaft is levitated and rotated within the cylinder and
> would therefore not be prone to normal wear and tear.

I think the magnetics running close to absolute zero so the blades could just have small magnets on them would be killer.. Would kinda be bad if the liquid used to keep it at absolute zero leaked out though. Could you imagine - Why is this cvarpet so crunchy..and cold too!