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New superconductor microprocessor yields a substantial boost in efficiency

spectrum.ieee.org

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Re: New superconductor microprocessor yields a substantial boost in efficiency

#181

Post by qayxc »

faeyanpiraat wrote: post #134
tromp wrote: post #125

This microprocessor composed of some 20k Josephson junctions appears to be pure computational logic. In practice it will need to interface to external memory in order to perform (more) useful work. Would there be any problems fashioning memory cells out of Josephson junctions, so that the power savings can carry over to the system as a whole?

If you compare cpu power usage with ram power usage, you'll see ram is already quite efficient, so even if traditional ram connected to the said microprocessor cannot be brought under the magic of this method, it might work. (Haven't read the article, or have any expertise in this field, so I might be wrong)

Cryogenic memory can be orders of magnitude more efficient than traditional RAM, even taking the cooling into account.

Re: New superconductor microprocessor yields a substantial boost in efficiency

#182

Post by whatshisface »

jessriedel wrote: post #127
whatshisface wrote: post #104

Earlier quoted context omitted.

It also doesn't change the fact that smaller devices are harder to put wires on - but they're both polynomial scaling factors that other polynomial scaling paradigms could cancel out.

The topic of discussion is datacenter vs. an extremely small cryocooler. What is the other polynomial scaling paradigm that would cancel out the datacenter's advantage?

The effectiveness of thermal insulators and heat pumps. If they make the cost difference negligible then other costs will dominate. We're talking about future decades of material science advancements here, a lot is possible.

Re: New superconductor microprocessor yields a substantial boost in efficiency

#183

Post by physicles »

faeyanpiraat wrote: post #129
mindvirus wrote: post #106

Earlier quoted context omitted.

Fun aside I learned about recently: we don't actually know if the speed of light is the same in all directions. So it could be 5+1=6 seconds or some other split. https://en.m.wikipedia.org/wiki/One-way_speed_of_light

There is a Veritasium video really fun to watch which exmplains with examples why you cannot measure one way speed of light: https://www.youtube.com/watch?v=pTn6Ewhb27k

Yes! In uni I had this idea for a program that would triangulate where lightning struck by having multiple computers across campus listening for thunder, then measuring the difference in arrival times of the thunder. Like GPS in reverse.

Soon I realized I’d need the computers’ clocks to be as in-sync as possible, which in turn requires one-way latency calculations. I spent an hour diagramming with pencil and paper until I convinced myself it was mathematically impossible or I wasn’t clever enough to find the solution.

Looking back, I was more worried than I should’ve been about this (wired latencies are usually far less than 5ms, which for sound is ~1.5m) and less worried than I should’ve been about the fact that thunder isn’t anything close to a point source of sound.

Re: New superconductor microprocessor yields a substantial boost in efficiency

#184

Post by gpderetta »

qayxc wrote: post #173
nicoburns wrote: post #168

Earlier quoted context omitted.

Some things have improved a lot. Remember how long it took to boot a 2009 PC. I suspect if hardware perfromance stagnates then software optimisation will develop again.

Counter example: a C64 booted pretty much instantly back in 1983 ;) You could load and start an entire game on that thing (albeit from a ROM cartridge) in less time than a 2000-era PC took to just POST :D So PCs were a regression in performance in that regard compared to 1980s home computers and micros.

I remember veeeery long load times from tape...

Re: New superconductor microprocessor yields a substantial boost in efficiency

#185

Post by gpderetta »

inglor_cz wrote: post #92
reasonabl_human wrote: post #83

Earlier quoted context omitted.

I wouldn’t want to be on call when something breaks on the moon.... Astronaut DRIs?

"Oh no, we bricked a lunar computer! Go grab your pressure suit, Mike! Back in a week, darling... Tell your mother I won't be attending her birthday party."

Obviously we will use a replaceable army of unknowing clones to service the machines. Cheaper to just defrost a new one than sending someone up.

Who volunteers as the original?

Re: New superconductor microprocessor yields a substantial boost in efficiency

#186

Post by namibj »

centimeter wrote: post #156
the8472 wrote: post #18

> We use a logic primitive called the adiabatic quantum-flux-parametron (AQFP), which has a switching energy of 1.4 zJ per JJ when driven by a four-phase 5-GHz sinusoidal ac-clockat 4.2 K. The landauer limit at 4.2K is 4.019×10^-23 J (joules). So this is only a factor of 38x away from the landauer limit.

> The landauer limit at 4.2K is 4.019×10^-23 J (joules). At room temperature.

That number checks out to be accurate to just over 4 significant digits. Divide the 4.019×10^-23 J by 4.2 K and ln(2), and you get a result just a hair smaller than the Boltzmann constant.

Unless the formula at [0] is wrong, in which case my calculations would also be wrong.

[0]: https://en.wikipedia.org/wiki/Landauer%27s_principle#Equatio...

Re: New superconductor microprocessor yields a substantial boost in efficiency

#187

Post by c1ccccc1 »

jetrink wrote: post #57
benibela wrote: post #54

Earlier quoted context omitted.

In Sundiver by David Brin they put all the heat in a laser, so they can beam it away from their craft

Is it possible to do this without violating the second law of thermodynamics?

In theory, I think it is possible. The laser light just needs to carry away entropy, which can be achieved by modulating the beam so that it contains information. Of course, you'll deplete your batteries to power the beam, and the laser itself will have inefficiencies. So with current technology, the system would likely generate more heat than it removed. A civilization with really good engineering could probably make it work, though even in that case, it would still use many joules of free (i.e. usable) energy to remove 1 joule of thermal (waste) energy.

A much more efficient method of heat removal would just be to have radiating fins. So you're still converting heat into photons, but you lose much less energy in the process, because the photons you're radiating have a higher entropy.

Re: New superconductor microprocessor yields a substantial boost in efficiency

#188

Post by joshspankit »

delecti wrote: post #169
joshspankit wrote: post #166

Earlier quoted context omitted.

There are some places where the cost of the ticket goes up the higher you are above the limit. Assuming it’s a school zone in one of those areas (pick whichever one you can answer for), what would the cost be then for going 28.4 mkm/hr?

Fortunately you could quickly get to a jurisdiction that didn't extradite.

Hahahaha! Well played

Re: New superconductor microprocessor yields a substantial boost in efficiency

#189

Post by throwaway2048 »

qayxc wrote: post #171
AnIdiotOnTheNet wrote: post #43

Earlier quoted context omitted.

Considering that many modern interfaces are somehow less responsive than ones written over 20 years ago even when running those programs on period hardware , I feel certain that you are right.

This is a very complex topic and there's a bunch of reasons for that. And no, software efficiency isn't even the main factor. Not even close. Just a few pointers: polling on peripherals instead of interrupts (i.e. USB vs. PS/2 and DIN) introducing input lag, software no longer running in ring-0 while being the sole process that owns all the hardware, concurrent processes and context switches, portability (and the req…

I don't think laggy electron apps have much to do with usb devices and ring 0.

Re: New superconductor microprocessor yields a substantial boost in efficiency

#190

Post by MR4D »

yazaddaruvala wrote: post #118
ajuc wrote: post #105

Earlier quoted context omitted.

> IMO, The fact that it's only 38x the minimum is MIND BLOWING. It's like if someone made a car that drives at 1/38th the light speed.

For anyone too lazy to math, its a car that can go: 28.4 million km per hour (i.e. 17.6 million miles per hour) I wonder how much that speeding ticket would cost. Disclaimer: Assuming the one-way speed of light is 300k km/s

> I wonder how much that speeding ticket would cost.

Depends on the frame the officer is viewing you from, I suppose.

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