Hitachi Demos Water-Cooled Notebooks

Sprocket writes: "Water-cooled processors, currently the domain of supercomputers, high-end servers, and garage hobbyists, may be about to enter the mainstream. Hitachi has developed a prototype notebook PC that uses a water-based solution to cool down its Pentium 4 processor and is planning to commercialize the product for corporate users in the third quarter of this year... read more"

Comments

Kits already available

[Jucius Maximus]

You can already buy water cooling kits for your PC. (This company is accepting backorders.)

Why not better than water cooling?

[evilpaul13]

Like a liquid that doesn't conduct electricity, isn't caustic, and isn't extremely sticky when dried? It would seem to me that would make for easier repairs in the future and make for a safer investment in an unproven application of cooling technology.

People expect reliability out of their performance laptops, afterall.

Re:Water-cooled

[bobdole369]

I think the Dreamcast had a heatpipe. Lots of laptops have heat pipes (basically a tube under certain pressure and a bit of an angle with a few drops of water in it, in normal state it is liquid, that under heat cause the water to turn to vapor, migrate away from the heat source, evaporate and drip back down the tube into vapor again.) Not new at all, and very passive... Not actively pumped about like this is....

just what i need, a $3000 portable coffee warmer

[Indy1]

honestly, isnt a P4 in a notebook a complete and total waste? The main performance bottleneck in a notebook anymore is the harddrive, not the CPU. The whole idea of a laptop is to be able take it to various places and be able to run it for a few hours on the battery. With the kind of power the P4 sucks down, you can kiss that goodbye. Add in fans to cool down the processor and/or water, and more of your battery goes bye bye. You'd need DDR to get the most out of the P4 as well, sdram + P4 is horribly slow and Rambus generates huge amounts of heat, which we all know is a no no in a notebook. I'm sorry Intel, but not everyone wants or needs a Marketing Processor (which is what the P4 really is, marketing over engineering) in a notebook. Give me a cool running low power Mobile P3 any day of the week.

Repairs..

[Werelock]

So instead of ~$400 to fix a broken display they could end up paying for the whole unit when the water drips/sprays all over the keyboard and then down to the inards. Brilliant...

Personally, I'd have engineered the water tank to the bottom of the unit or as another drive bay. Gravity would force the water from a broken unit outside the laptop.

How is this a good idea?

[RainbowSix]

Watercooling requires a way to move that water, ie, a pump. Moving parts that require power, and the problem is that you still have to get x watts of heat out of the water at the other end. I think the current use of a heat pipe is much better than watercooling. The only "movement" is the phase change powered by the heat itself, and so there is less chance of failure.

Re:Logical choice

[FFFish]

Is water the logical choice for cooling? I'd have thought oil would be. Particularly as a synthetic oil should be non-reactive, quite unlike water. Although, come to think of it, that'd eliminate built-in product failure...

Re:Unveiled where?

[shimpei]

Here is an article in Japanese, with pictures, linked from a Slashdot Japan article.

By the way, the revolutionary part about this laptop is that it uses a mechanical pump to move the hot coolant to the radiation panel at the back of the LCD, whereas traditional cooling mechanisms uses the palmrest and/or the bottom of the laptop to dissipate heat in addition to the air fan. The idea is that

• a pump is much more reliable than a fan, because it doesn't move as fast or ingest foreign dust particles all the time; and
• 2) heating the back of the LCD affects the user experience less than with the palmrest or the bottom.

Also, before people start screaming about how big the water tanks are in the photos, the article says that the tanks were deliberately enlarged to emphasize the point of these prototypes, and they will be reduced in production models.

Re:just what i need, a $3000 portable coffee warme

[FFFish]

Give me a Pentium-I 300Mhz with sixteen hours battery life any day of the week...

(I figure if they can make a P4 run four hours, the P1 should be good for at least four times longer!)

Re:Logical choice

[khuber]

>Is water the logical choice for cooling? I'd have thought oil would be.

I wouldn't think that. Water has a higher specific heat and much higher thermal conductivity. Water is not "reactive", plus when you spill water, it evaporates.

-Kevin

IBM's solution goes beyond just water cooling

[jmichaelg]

A close read of the IBM article reveals their solution is to use a heat pipe instead of what most hobbyist are doing. Heat pipes are sealed cooling systems that exploit the fact that it takes 100's of times more heat to vaporize water (or other coolants) than it does to raise water 1 degree. To get water to vaporize at around 25-30 degrees C, you have to create a vacuum inside the coolant pipes.

Heat pipes are an old idea - they were used in the Apollo program. IBM's key addition to the technology is developing a hinge that efficiently transfers heat between the laptop's body (the heat source) and the display (the heat radiator). There isn't much info in the article referenced in the original post to figure out just what Hitachi thinks is original.