idea for lower ln2 temps

[kalen]

Has anyone every tried lowering the pressure that the ln2 evaporates at?
I was thinking you could do it like this:
http://i33.photobucket.com/albums/d92/shredator/ln2.jpg

Whaddya think?

[n00b 0f l337]

It works and its well known. It has been done I beleive. But the cpu doesnt normally like that cold.

[stealth17]

bump>.......

[Thrilla]

Things becomes superconductor under xtreme coldness... soooo, if your CPU becomes super conductive.... hmmm I'm not sure on this one, explode? Someone should give it a try with old PIIIs XD

[IYP]

dident chilly do something like this at one point?

[SoddemFX]

Chilly has done it, i think Fugger made a quote someting like "LN2 boils at -205C in Las Vegas"...

This is not superconductivity and semiconductiors dont behave like this. In the silicon with very low temperatures electrons just stay in the valence band and the band gaps energies become all messed up. In general lower temperatures mean less conductivity with a semiconductor...

Tom

[afireinside]

It works but it's TOO cold for most CPUs so it's better to hand pour.

[[XC] moddolicous]

What would the base temps be on something like this? Below -200c? Maybe with the P4 670 we could start it at some low temps then just let it get colder. Maybe we could see 8ghz this way.

[afireinside]

Nope... The mass of the solid copper units Team Japan uses gives an advantage over this method as well. An evap like fugger/chilly1 would get run over by the heat at 2v 7.4ghz+. HIGH voltage and high clocked P4s/A64s (I'm talking 1.9v+ 3.6/7+ clocks) or high clocked dual cores need large mass coolers. You could have -500C but if the cooler doesn't have the mass to handle the heat it won't matter.

[[XC] moddolicous]

Alright, I kinda understand what you mean.

[SoddemFX]

Why does the physical mass of the evaporator have anything to do with heat transfer ability?

The higher surface area as a bi-product of the larger mass evaporators / tubes i can see having an effect but actual mass shouldnt have any effect of long term high load or low temperatures...

Tom

[afireinside]

Maybe someone like kingpin who knows far more about this than me can say it right but you have to have a large amount of mass to handle high heatloads otherwise it can't keep up. Why do you think solid dry ice units hold load FAR better and at lower temps than brazed ones?

[SoddemFX]

Hi AFI,

I'd always thought that because the majority of containers have very little surface area on the base, the majority being on the walls. The solid containers have a wider conduction path to the walls because they can be made this way. No one has or would taper down pipe with 1/2" wall then solder / brase to a base but if they did...?

This doesnt have to do with mass, you just have so little surface area at the base that you need wider conduction paths to use surface area elsewhere.

The mass is a bi-product of providing higher conduction not a soloution in itself. A soloution is more surface area :)

In my opinion...

Tom

//I like your name, brilliant music...

[ilkkahy]

This doesnt have to do with mass, you just have so little surface area at the base that you need wider conduction paths to use surface area elsewhere.

The mass is a bi-product of providing higher conduction not a soloution in itself. A soloution is more surface area :)

I have the same point of view too. I think term "conduction path" is very good. Im currently working on a solid container that has better conduction paths and bottom surface area than present ones.

[k|ngp|n]

Hi AFI,

I'd always thought that because the majority of containers have very little surface area on the base, the majority being on the walls. The solid containers have a wider conduction path to the walls because they can be made this way. No one has or would taper down pipe with 1/2" wall then solder / brase to a base but if they did...?

This doesnt have to do with mass, you just have so little surface area at the base that you need wider conduction paths to use surface area elsewhere.

The mass is a bi-product of providing higher conduction not a soloution in itself. A soloution is more surface area :)

In my opinion...

Tom

//I like your name, brilliant music...

IMO the best performing DI/ln2 containers are the ones the HAVE THE MOST MASS NEAR THE SOURCE OF THE HEAT(core). For example...a central "core" or "pole" design.
I am sure others will disagree but that is my direction.
I thought of tapering down my container at the bottom for looks, but for functionality it went against what I orignally felt was best. I didnt want to remove mass from a critical area so close to the die., I did the opposite acutally put as much there as the max measurements would allow. 70% of my containers mass is 3-4 inches or so from the base.

[ilkkahy]

IMO the best performing DI/ln2 containers are the ones the HAVE THE MOST MASS NEAR THE SOURCE OF THE HEAT(core). For example...a central "core" or "pole" design.
Naturally the best place for that mass is over the core where all the heat comes from. Well at least as long as it doesnt prevent ln2/co2 getting close enough to core (thats why the central pole is way better than just 2" thick bottom). But i would talk about the conducting paths to surface area instead of mass. The word mass is perhaps easier to comprehend though.

[stealth17]

So how would a 10" central pole fair?

[AruisDante]

Yeah, surface area is what's important. It's basic physics. the equation for heat dissapation is T'=-Ak/cm(T-Tout), where A is surface area, cm is calories per minute, k is thermal conductivity, T is temperature, T' is change in temperature, and Tout is the outside temp (temp of the other material that comes in contact with the surface dissipating heat). As surface area increases, the change in temperature also increases, and thus more thermal energy is dissipated. the mass of the object has no direct relation to the dissipation of heat, only surface area.