Blowing air between the hs and cpu?!

[evolotion]

I was thinking...If you were to blow air (using a fan and some kind of funnel) around the core between the hs and the processor package, how good the cooling effect would be?
Iv heard people saying they use copper shims to cool the processor package(the ceramic bit) but id imagine that this would be beter..
Your views please??

Im contemplating trying it when i get my hands on a duron, il post the results if/when i get them..

 

[Spoooon]

Copper shims have been shown to increase core temps.

"Intuitively, you would think adding a copper spacer of the kind pictured above would add to CPU cooling. Increase the cooling area of the heatsink to the CPU package and it should run cooler. Anything that can help to tame the flaming AMD CPUs has to be a good move."

Toward the end of the article...

"The moral of all this: Save your money and don't buy a CPU spacer expecting a temperature benefit. If you want additional cooling, aim some fans at the back of the motherboard. Treat the motherboard like another heatsink and cool it accordingly."

Quotes from Overclockers.com

 

[CocaCola5]

I have a theory why copper shim or any shim for that matter is bad for core cooling. Without a shim, the core gets the HS to itself, its the only part of the chip touching the HS. With a shim in place, the core have to share the HS with the rest of the surface of the processor. The result I think is, without the shim, the core runs cooler but the chip surface runs hotter. With the shim, the core runs slighty hotter but the chip surface runs cooler.

 

[MrDudeMan]

so basically the spacer is crap...? id rather have the core run cooler and just stick a fan on the back of the mobo. i have a 60mm fan about 5mm away from the back of the mobo and its tilted a little so the air can escape...that helped a LOT.

 

[006agent]

same here. cept i have a 92mm one. dropped my temp by 3-4c

 

[Mikewarrior2]

Shims Do not, in any way, benefit cpu cooling. If anything, they increase core temp.

Why?

Because teh shim touches heatsink on one side(a warm heatsink at that) and cool ceramic pcb on the other. Copper, being an excellent conducter, takes heat from heatsink and conducts it inot the PCB. hence warming the pcb then cpu. While this is a very miniscule amoung, the effect is a non-cooling effect. Yes, they're okay to use, but only if you are using it for heatsink mounting. To think that they are aiding in cooling is a mistake.


Mike

 

[evolotion]

I agree about the shims hence my idea..If there is a pocket of air between the procesor package and the hs this air wil get hot +stay hot but if you low cold air in its place, the package could get cooler..which is nice!

 

[McBoo]

Ummm, Wouldn't the fan on the backside of the MB just cool off the thermister itself and skew the results? I'm not sure of your setup, but on mine the thermister is located in the center of the socket below the core. It sounds like an interesting idea, but I'm unsure if it'd affect a real change in core temp.

 

[Mikewarrior2]

McBoo,

You're absolutely correct. Cooling teh back of the mb cools the thermistor, further skewing the readings. As if they weren't bad already.(see sig).


Mike

 

[Basilisk]

I first agreed with McBoo's comment... then paused: cooling the m/b isn't "just" cooling the sensor, it's also cooling copper-alloy wires leading to the CPU. Sure, the sensor data's badly flawed and is led further astray when cooling the m/b, but... wouldn't 462(?) wires leading to the CPU itself have a meaningful cooling (heat-extracting) effect?

On the earlier topic: if shims raise the temp' of the substrate, the that substrate isn't well connected thermally to the CPU so a warmer substrate may not effect the CPU temp' much at all -- it may -just- heat the sensor. If that's the case, the warmer substrate may cool the CPU by increasing heat transfer from the CPU -- while raising the -apparent- temperature [the sensor].


Ignoring that blather: I'd like a shim [thermally non-conductive?] just to back a copper plate to spread heat-transfer from the CPU more broadly across a heat-sink's base... better yet, a h-s with an embedded copper plate for that purpose. 'Haven't looked around for these. 'Nor, probably do I really need any of this silliness!

 

[Mikewarrior2]

Basilisk,

No, it doesn't. Because in actuality, very little heat passes in or out of the pins. And cooling the back of a mb will cool the thermsitor much mroe than cooling pins, and therefore further skey the thermsitor readings.


Mike

 

[006agent]

you all need help...i think you are posting because you are bored.

skewing the reading...what.
look people. we are talking about a SEALED chip. the pins are buried in a plastic case. not to mention the the thermo.. it in the middle of all this.

i might give you a .5c skew.

any fan helps..as long as you don't cancel them out..ie positive and negative pressure.

 

[Viperoni]

I can hear Mike breaking out that whip at this very second, on 006

006, the point of the thermistor is to read temps.
If you dont get accurate readings, what the frig are you trying to do?
Agreed a fan will cool off the underside a bit, but frankly, I wouldn't even bother.

 

[006agent]

mine is strictly there to take away heat build-up in the cpu area...my case is a wintunnel.

 

[Mikewarrior2]

A) The socket IS NOT SEALED

B) COmpression factors of readigns versus core temps has shown to average aroudn 3 to 4, and up to 6 at times.

What does that all mean? There's a reason socket-thermistors under-read core temp. Its because, from where they read temp, they only measure a fraction of core temp change. Look at the side cut picture in my sig, the heat must pass through 7 layers of heat-resistant ceramic PCB before being measured by the thermsitor. IT IS COMPLETELY crap for readings. Cooling the back of the mb behind it cools the resistors in the socket, hence cooling socket-air and further skewing a thermsitor that already reads too low.


Mike

 

[smp]

Dammit.. AMD really has to enable that temp reading diode in the chip (if there really is one).. this sh!t is just ridiculous..

 

[Mikewarrior2]

If chips weren't burning up, there would be no issue.

But since:

AMD refuses to "RMA" overheated CPU's, they should provide a way so that the user can know its overheated. Often times, they'll have "readings" of 50C, and the chip will all of a sudden die.


Mike