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<Link> Helical Logic Computation
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(06-27-2013, 01:41 PM)Drashner1 Wrote: <snip>
It seems to me that comparing the Ultimate Chip and this device is also somewhat like comparing apples and oranges. The UC is intended to operate at 'room temperature' pretty much while this tech is described as operating at cryogenic temps from what I can gather (haven't had time to read the whole article, sorry). And I also recall Adam stating when the UC was first introduced that it is the best possible within the temp range described and using phonons since they are most efficient in these conditions. That certainly leaves the door open to many other devices that might operate under very different conditions. A super-cooled or actively cooled UC might be much more powerful, although such hasn't been described yet.

To date, we do NOT have reversible computing really addressed in the setting, mainly because we haven't been able to find much solid info on it. If it can be made to work it may have a major impact on computation. That said, one thing I seem to recall is that it is overall somewhat slowed down by the need to perform all its calculations in reverse in order to 'cancel out' the entropy or energy dissipation from doing them initially. So this may also slow things down overall a bit. Although maybe this tech gets around that somehow.

<snip>

Thanks!

Todd

Computation is equivalent to a heat engine. For a good review article on the subject, see:

http://tnt.phys.uniroma1.it/twiki/pub/TN...machta.pdf

As with any heat engine, the Carnot efficiency *increases* as the differential between system and reservoir increases. That is, a computer operating at near zero is typically less efficient than one operating at room temperature, which is less efficient than one operating at neutron star temperatures, i.e.:

Cryogenic << Room Temperature << Fusion temperatures << Big Bang

I added "typically" because there are interesting quantum effects that may change this in some cases, e.g. interstellar chemistry mediated by quantum tunneling which recently appeared in the literature. It's far from certain that this is general.

BTW, this is the reason "cold fusion" i.e. muon-catalyzed fusion didn't work out. You get 10-15MeV of energy per deuteron but you spend 200MeV for the muon, so you need nearly a score of collisions just to break even, but collisions are exponentially unlikely. Raise the temperature and it's more probable, but then it isn't "cold" fusion anymore.

With respect to reversible computing, again, any Turing-complete computation can be broken down into a series of steps (i.e. an algorithm), for which you pay nKT energy to complete that step in a given timeframe according to Landauer's principle (where n is the number of bits you must erase for that computation). You can pay less than nKT energy per step, but then your timeframe for that step increases by the same factor.
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Messages In This Thread
Helical Logic Computation - by JohnnyYesterday - 06-25-2013, 03:41 AM
RE: Helical Logic Computation - by Rynn - 06-27-2013, 04:57 AM
RE: Helical Logic Computation - by Tachyon - 06-26-2013, 04:11 PM
RE: Helical Logic Computation - by Tachyon - 07-03-2013, 06:07 AM
RE: Helical Logic Computation - by stevebowers - 06-27-2013, 12:55 AM
RE: Helical Logic Computation - by Drashner1 - 06-27-2013, 01:41 PM
RE: Helical Logic Computation - by Tachyon - 07-03-2013, 06:31 AM
RE: Helical Logic Computation - by Rynn - 06-28-2013, 07:00 AM
RE: Helical Logic Computation - by radtech497 - 06-28-2013, 10:10 AM
RE: Helical Logic Computation - by Drashner1 - 06-28-2013, 01:46 PM
RE: Helical Logic Computation - by stevebowers - 06-29-2013, 09:45 AM
RE: Helical Logic Computation - by Drashner1 - 06-29-2013, 09:50 AM
RE: Helical Logic Computation - by stevebowers - 06-29-2013, 11:17 AM

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