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Notebook Cooling Strategies
An Anonymous Coward writes "As components shrink, heat control becomes critical. Hitachi will sell water-pump cooling for notebooks while Sony has fancy, twin-fan ductwork in its new Vaio laptops. Meanwhile, a ceramics company that's testing a coating that's highly efficient in radiating heat away from processors and race car engines." We mentioned the water-cooled notebooks earlier.
But it keeps an army of fans to keep my desktop cool enough to runs stabely, and it sounds like an aircraft carrier.
"The United States has no right, no desire, and no intention to impose our form of government on anyone else." - Bush 05
I used to have a Vaio, and like others, I have expereinced leg cooking heat when using it as a 'laptop' (that is if the battery ever lasts that long). Plus, the fan was noisy - there is an option in the Sony Power management software to switch the fan off, however, i think performance is comprimised. :-)
I've now got an iBook, and not only do my legs stay cool.. it is also extremely quite (no fans, just uses convection currents if I'm correct), the only sound being the harddrive below the left palm rest.
Personally, I think Apple notebooks are the quietest. Less heat/noise = less energy is wasted thus, longer battery life...
Fight Crime - Shoot Back!
I have a Dell C800 (1ghz) laptop. When the fan comes on, people look over...when the second comes on, people dive for cover. (Well, maybe they are not really that loud) It would be nice if they could sync the RPM's a little better so it doesn't have the "whir" "whir" "whir" sound. That's the price I have to pay for a 1st gen gightz laptop.
I've got some copper piping stuff going from my CPU to the fans, which supposedly has some super heat conductive stuff in it.
-Pete
Soccer Goal Plans
1) We're going to finally start seeing hard-drive free systems. RAM is actually cheap enough that one to two gigs, living off an independent power supply, should be price competitive with a ten gig hard drive. Though XP might need to be shaved down a bit to fit in such a small amount of space, the increased system speed and vastly decreased amount of moving parts should make a significant difference in both power consumption and heat generation(the two are arguably the same thing). On the flip side, repeatedly pulsing that much memory might actually drain more power than I'd guess, and battery life on the RAM might not extend past a few days. In this case, I could still see a microdrive + RAM combo, or even a system that flat out just ran off a 2gb microdrive.
2) CPU heat will eventually be turned into a power source. Heh -- it's there, it's dependable, and if nothing else, it'll supplement primary power sources. I don't know how efficient electrical heat->power systems are -- I doubt Peltiers are going to work too well here, and we ain't sticking a turbine into a laptop (though Microfluidics just got much, much more interesting!). So this is the "five-to-ten years down the road" likelihood.
3) I feel like sounding like an idiot for a second, so I'll put this out there just for someone else to discredit: What about mechanical compression? Imagine a spring on the side of a laptop that needed to be pushed in periodically, but would absorb heat by slowly expanding. It'd be annoying, but each time the spring was compressed, heat should be lost reasonably harmlessly to the user's musculature. I'm sure this doesn't work, but I'd be interested in knowing the history of why not.
Yours Truly,
Dan Kaminsky
DoxPara Research
http://www.doxpara.com
Notebooks are doing some incredible things in the way of upping power/features/screen size/etc while shrinking drastically in size and weight - and ending up with some problems such as heat dissipation. In my mind the biggest advantage to a notebook apart from its' portability, is the weight issue - not size. Surely giving quite a bit more space inside the box isn't going to add all that much to weight, may bring a laptop an extra half inch higher while increasing air cooling possibilities incredibly.
I can see that laptops have a high 'just plain sexy' component, which isn't likely to go away. A rep in a former workplace of mine insisted on one of the top Compaq notebooks, when his only need was for a PDA. Thin does sell for many people, but for me an iBook or TiBook would be just as nice at twice the depth.
a grrl & her server
can't resist....
1stly. No mac comes in fruity colors. Ha.
2ndly. In the short run its cheaper to use a water cooling, but long run its cheaper to make all mobile chips be more power efficient. This is b/c you do research once. (fab costs aren't higher for more power efficient chips) Whereas every laptop has to come with water cooling, so it costs more.
Looking inside my Apple PowerBook G4, I see things that look very much like pipes traveling away from the CPU to other areas of the laptop (areas which tend to get rather warm), and I assume these are the phase-change heat pipes I heard about a few years back. Whether Apple is the only company doing this, I don't know, but it is sure cool, pardon the pun. The fact that the G4 consumes less power is also a big help.
I'm now going to go off on a tangent, mentioning various aspects of physics that are barely relevant, but pretty damn cool. First of all, a bunch of people have suggested using the heat as a power source. While you can use temperature gradients as a power source (think thermocouples), it's damn unlikely to be practical here (the power harnessed would be trivia).
Second, I'd like to point out that heat dissipation is becoming an increasingly-important problem in CPU design. Although we're not there yet, there are theoretical limits on how efficient non-reversible computations can be, in a thermal sense. In other words, each time you manipulate a bit (to be really picky, each time you reset a bit), it must produce a certain amount of heat. This could be the hard limit that breaks Moore's Law for classical, non-reversible computers. The way around this is to use reversible gates (such as in quantum computing), which have no such minimum heat cost. For instance, the XOR gate can be replaced with the controlled-not (CNOT) gate, which is reversible. This would require a major reworking of how we build computers... But I digress... Suffice it to say, heat is a big problem, and it's only going to get worse.
...typically, heat-related coatings on engine components are designed to keep heat *in*, so belts, hoses, and other non-metal parts don't get fried.
I guess I could see an application to radiators -- parts that are specifically designed to radiate heat -- for some "heat-phobic" coating, but it seems highly unlikely. 1) Drag racers are concerned about a quarter mile that goes by in somewhere between 4 and 10 seconds; there's not enough time for heat to make it to these fancy coatings. 2) Road racers sustain speeds of 100mph+, and wind alone does a heck of a cooling job at those speeds.
I can't say the racecar angle is bunk, but I can say it's the reverse of my limited experience in that field.
-b