New 3D CPU Water Cooling Method

captain igor writes "According to this story on Wired News, a new company launched by researchers from Stanford has come up with a way to layer a silicon network of tiny tubes on top of a microprocessor. The system then uses a solid-state motor (no moving parts!) to pipe cold water through the silicon network. According to the article, this system can handle 1000 watts (yes, a kilowatt) per square centimeter."

Comments

Re:It's not a motor

[CaseyB]

By definition, a motor turns, therefore it has moving parts.

No. A motor is by definition "one that imparts motion". This device certainly qualifies.

Re:G5 laptop now possible?

[Cecil]

No, actually, they're not because the G5 is excessively hot, nor are they for show. They are for maximizing the efficiency of the 9 (VERY low speed) fans in moving heat out of the system with minimal airflow

People assume that because the G5s have a extremely well-engineered cooling solution that the G5 is also extremely hot. It's simply not true, it's all about noise reduction.

Re:stove top boiling water experiment

[Thagg]

Say water goes in at 30 degrees C and comes out at 50 degrees C. According to the spectacular Google calculator, 1000 watts is 239 calories per second, and it takes 1 calorie to increase the temperature of 1 cc of water 1 degree C, so you'd have to move 239/20 or about 11 cubic centimeters of water through the cooler every second assuming a delta-v of 20 degrees C. Doesn't sound unattainable.

thad

Re:stove top boiling water experiment

[rcw-home]

This is a lot easier if we stick to metric units.

The factor they always leave out is how much of a temperature rise one can tolerate at the heat sink. Let's assume that the incoming water will be no higher than 40C and the CPU can become no hotter than 60C - that's 20C rise.

1 kilowatt is 1000 joules per second, or 238 gram calories per second. Conveniently, a gram calorie is the energy needed to raise a gram of water one degree celcius. For water, one gram is also one milliliter. So, a single gram of water will be raised 238 degrees C in one second. We don't want it to be raised more than 20C, so we need to exchange water at a rate of 238/20 = 11.9 mL/sec.

Heat sinks aren't perfect - the outgoing water will always be colder than the CPU. Let's pretend that this sink is 50% efficient (the CPU rises to a temperature, relative to the incoming water, of twice that of the outgoing water). Ergo, we need 23.8 mL/sec.

How is this a problem?