Liquid Nitrogen Beats Air Cooling (Again)

joe094287523459087 writes "some guys used liquid nitrogen cooling via a cardboard tube to get a 20,000 3D Mark score. you can see the frost forming on everything - wouldn't the moisture from the condensation kill the board?" The Muropaketti guys had already done this with their microprocessor. Apparently the next step was to speed up their graphics card to match.

Comments

Re:Frost everywhere

[kenthorvath]

The water pulled from the atmosphere would be mostly deionized and non cunductive. Just like those old oil based cooling systems that you actually submerged your components in and ran through a refridgerator.

Thermal shock

[panurge]

Someone mentioned this. Forget the solder joints for a moment (though the pure tin used on some boards now will actually crumble after a time at liquid nitrogen temperatures) the contraction of the case of the CPU will put stress on the pins, and the temperature differential between top and bottom of the case will put stress on the die joints.
Also, if I remember rightly, the actual drain currents of the transistors goes UP because the resistance is going down (which is why you can overclock, of course.)Although the lowered temperature means the tracks will not be damaged, there may be other effects of the increased current density in longer term degradation of the die. If there is track necking anywhere, this might be a potential failure point.
You might also expect damage to the epoxy cladding of the graphics chips, as the contraction pulls the epoxy away from the filler. This could result in the epoxy eventually becoming porous and the system failing due to moisture penetrating the cladding, just like 6502s etc. used to fail before anyone realised that glass fibre filler could wick water in to the die.

The answer is to follow Seymour Cray and sink the entire system in cold fluorinert, using the total loss nitrogen system, or much cheaper dry ice, to keep the temperature at a sensible -45C or so. But that wouldn't be nearly so spectacular, would it?

This is all a bit like our local hot rodders who can't safely make it to the next town and back for fear the engine will blow up on them. Even so, it would be nice if Intel would release some of the data they doubtless keep on this sort of thing.