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PC's Waste Heat Could Add To Processing Power
Urchin writes to tell us that physicists working in a new field called "phononics" claim that waste heat from a processor could actually be used to add to its power. "Crunching data coded using photons — photonic computing — is one example, and in 2007 researchers built the first workable optical transistor. But now the idea of computing using heat flow is gaining popularity among applied physicists. Heat travels through solid materials by means of phonons — ripples of vibration passing through a series of atoms. Those ripples can be used to send and store data in digital form: one temperature is read as 0 or 'off' while a second, higher temperature is interpreted as 1 or 'on.' Provided that the thermal memory is well insulated, it can keep its temperature — and data — intact for a long time."
I might not entirely understand this, it sounds like this is a whole lot of work for not much result. What happens if you get temperatures that are precisely inbetween 0 and 1 values? What effect does the processor's fan and/or heatsink have on said values? Why bother?
Interesting...kind of like a turbocharger for a CPU.
Lisa, In this house we obey the laws of thermal dynamics!
That said. It may save some power converting loss head back again making it more efficient.
But they way that most people use computers I don't know if there is a benefit. We rarely run at full CPU Heat kicking.
If something is so important that you feel the need to post it on the internet... It probably isn't that important.
I wonder how long before this is used for something bad? Does this possibly mean that the sun, inhabited by an alien life form, has turned off the one's and zero's in an effort to relay the message GTFO!
FTFA:
Casati says practical physicists must rise to the challenge set by the theorists. Yet even if they can, phononic computing is unlikely to threaten electronics because phonons travel a lot slower than electrons. Li imagines that the two technologies will work together, in hybrid devices that perform some computation using waste heat.
I bet there are better ways to use this than PC computing
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I'm hooked on phononics. And quit making fun of my stuttutter!
"Provided that the thermal memory is well insulated", that basically means putting it on a different piece of silicon/on something else entirely, which kind of defeats the object as I see it.
While I haven't looked at this in great detail, it strikes me that achieving anything near useful density is going to very difficult due to entropy, and the simple fact that putting very small volumes at slightly different temperatures right next to each others quickly leads to a relatively uniform temperature distribution.
This sounds somewhat improbable/unfeasible to me...
There is no psychiatrist in the world like a puppy licking your face - Ben Williams
This, IMHO is an academic concept at best. State definition by thermal state has been done in research before but it is slow, and trying to collect the waste energy in the form of heat and re-use it as the byproduct in another state machine sounds a bit questionable.
Mechanical computers are viable as well, but not too terribly practical.
www.effectiveelectrons.com "chips that work" Analog, RF, Mixed Signal
Phonons travel at the speed of sound in their medium, which is 100,000 times slower than the speed of electrical signals or light. If you've got a phononic circuit running at a Ghz clock rate, signals can only travel a few microns. This size limit severely restricts the number of individual components you can have in your circuit.
Go light, or go home.
Phonons are just a very weird state of photons, for suitably high values of "very weird"--they propagate by the dipole interactions of the substrate, and are thus at the bottom an EM phenomena. But that isn't a very useful way to look at them (about as useful as saying that sound in air involves oscillatory motion of masses and thus could be considered a source of gravity waves).
Rather than asking "how do they fit into the standard model?" it makes more sense to ask "how tight is the analogy between phonons in a lattice and photons in a vacuum?" and "where does the analogy break down?" Note also that the analogy is pretty good in places (the governing equations are identical) so the concept is more useful than you think.
--MarkusQ
P.S. IANALP -- I am not a licensed physicist; I am not your physicist, and this is not physical advice. If you have questions about the laws of nature you should conduct experiments, not rely on the advice of people you meet on the internet.
The net gain in computing power would be negative, simply because everyone knows that heat causes computrons to decay into bogons, resulting in an overall loss of processing power.
Also, fans in a water-cooled system?
Yes, fans in a water-cooled system. You need fans on the radiators to extract the waste heat from the water. You can do it passively but that's massively inefficient. There are really two reasons to go with water cooling on a PC. You can do it to give yourself a bit more overhead in the overclocking department (since you can move a bit more heat using water and massive radiators, versus a individual heatsinks and fans), or you can do it for a silent system in which case you often need to under-clock the system and rely on convection either to cool the radiator, to circulate the water, or both. My gaming system is water cooled and overclocked and has 8 120mm fans, 6 on the radiators and 2 on the front intake grill (one of the radiators is setup as an intake as well, so it's actually 5 intakes, 3 exhaust).
Curiosity was framed, Ignorance killed the cat.
If I understand this properly (and it's not 100% guaranteed that I do), this sounds like an excessively complicated solution that would yield relatively little benefit. The "sandwich" idea from TFA sounds especially counterproductive, if external power is required to keep the hot side hit & the cold side cold.
Instead of trying to harness waste heat to eke out a fraction of a percent of extra processing power, here's an idea: how about sucking that waste heat into a small insulated pipe with a low-voltage van, and running that pipe down to my feet? It's very cold near the floor of my apartment, and some warm air aimed at my tootsies would be greatly appreciated while I use my computer.
Maybe this pipe could have a little door I could close in the summer, when the additional warmth would be less welcome.
Just once I'd like someone to call me 'Sir' without adding 'You're making a scene.'
Seems like a solid state thermocouple might be easier to use. I'd like to see some sort of heat pipe from the case to one, then use that output to power the screen (maybe not the main one but a smaller backup little screen??). I have no idea of the state of the art there though or what sort of useful electricity you might get from one. I have seen a kerosene lantern from Russia that uses a thermocouple to scavenge waste heat from the kero burning to provide power for a table radio.
At one of our compute farms, we actually pipe the waste heat into a local town as a low-cost house-heating solution (think steam-pipes, but lower quality energy.) It works there because even 100 degree hot air is nice to have when the outside temp is 0f.
To be fair, VTEC does allow for a milder cam profile at lower rpms, while allowing for a much more aggressive cam profile for additional horsepower at higher rpms. Maybe that's what the OP was getting at.
Its winter. There is no such thing as 'waste heat'. Every watt emitted by a computer is a watt that doesn't have to be emitted by the heater.
A computation is a process in which we take a memory area that may be in any randomly-chosen state, and reconfigure it to be in one specific state, corresponding to the return value of our computation.
This is a local reduction in entropy - reconfiguring that memory area into a single state out of the many possible. That means work has to be done, and there has to be an increase in the entropy of the Universe at large that at least exceeds the decrease in entropy in the memory chip. And that means heat.
Real Daleks don't climb stairs - they level the building.
At the lowest possible level, we're talking about electrons moving around. Every time you do an instruction, a bunch of electrons have to move from one place to another. On the way, they inevitably bump into things. Whenever that happens, you lose a bit of energy as heat. That's what the oh-so-common equation, P=(I^2)R means. The I is the current (moving electrons), the R is the resistance (things electrons bump into), and the P is the power (energy per second that you lose as heat).
As for what you read about (ir)reversible math, that does contribute as well. Consider a single bit of a register, where a zero is represented as 0V, and a one is represented as 1V. If that bit contains a 0, and I want to make it a 1, I need to pull out a bunch of electrons. If I am going to move the 0 that used to be there someplace else, then I could, theoretically, move the electrons there. In that case, the only loss would come from the very short distance that those electrons move. But if I am just getting rid of the 0, those electrons go to the 1V supply, and get sent back to the power supply and all the way back to the power company*. That's a longer distance, so there's going to be more loss. But even if all the math was reversible (i.e. no bits were ever overwritten, only shuffled around) there would still be loss. That's a purely theoretical system anyway - no one actually shuffles their bits around like that.
Hopefully that answers your question.
* Note, what I said here isn't actually true. The electron would never make it back to the power company, and is unlikely to even leave the chip -- electrons don't move that fast. But a current would be set up that goes all the way back to the power company, and a bunch of electrons along the path would move a little bit, like a sub-atomic conga line, so the loss of power is the same.