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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

#171

Post by qayxc »

AnIdiotOnTheNet wrote: post #43
layoutIfNeeded wrote: post #14

Earlier quoted context omitted.

>Imagine how programming and operating systems might look in a world where processing power is 80x cheaper. So like 2009 compared to 2021? Based on that, I'd say even more inefficient webshit.

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 required layers of abstraction and indirection), etc.

It's a bit cheap to blame developers while at the same time taking for granted that you can even do what you can do with modern hard- and software.

Everything comes at a price and even MenuetOS [1] will have worse input lag and be less responsive than an Apple II, simply because you'll likely have USB keyboard and mouse and an LCD monitor connected to it.

[1] http://menuetos.net

Re: New superconductor microprocessor yields a substantial boost in efficiency

#172

Post by whatshisface »

nicoburns wrote: post #167
jessriedel wrote: post #76

Earlier quoted context omitted.

Really. Vacuum casing is not even close to sufficient to set heat absorption to zero because of thermal radiation. And you can't just make the walls reflective once the cold object gets smaller than the wavelength of the radiation. The colder the object, the longer that wavelength.

What kind of wavelengths are we looking at for the kind of temperatures used in this article?

About 700 micrometers, almost a millimeter. That's from applying Wien's displacement law to the boiling point of Helium.

Re: New superconductor microprocessor yields a substantial boost in efficiency

#173

Post by qayxc »

nicoburns wrote: post #168
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.

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.

Re: New superconductor microprocessor yields a substantial boost in efficiency

#174

Post by marcosdumay »

ipsum2 wrote: post #154
Jweb_Guru wrote: post #100

Earlier quoted context omitted.

Not sure if you noticed, but Moore's Law died quite awhile ago now.

Moore's law is fine: https://en.wikipedia.org/wiki/Moore's_law#/media/File:Moore'...

Moore's law is bout the most economic die, not about always more expensive top of the line.

If you take those out, there is a very clear stagnation on that graphic.

Re: New superconductor microprocessor yields a substantial boost in efficiency

#175

Post by qayxc »

faeyanpiraat wrote: post #130
inglor_cz wrote: post #55

Nice, but requires 10 K temperature - not very practical. Once this can be done at the temperature of liquid nitrogen, that will be a true revolution. The difference in cost of producing liquid nitrogen and liquid helium is enormous. Alternatively, such servers could be theoretically stored in the permanently shaded craters of the lunar South Pole, but at the cost of massive ping.

I'm no physicist, but wouldn't you need some kind of medium to efficiently transfer the heat away? On the moon you have no atmosphere to do it with radiators with fans, so I gues you would have to make huge radiators which simply emit the heat away as infrared radiation?

> On the moon you have no atmosphere to do it with radiators with fans, so I gues you would have to make huge radiators which simply emit the heat away as infrared radiation?

Exactly. You can still transport the heat efficiently away from the computer using heat exchangers with some medium, but in the end radiators with a large enough surface area will be required.

Works well enough on the ISS, so I imagine it'd work just as well on the Moon.

Re: New superconductor microprocessor yields a substantial boost in efficiency

#177

Post by triclops200 »

6nf wrote: post #161
bananabreakfast wrote: post #132

Earlier quoted context omitted.

I think they were alluding to the fact that it is impossible to measure the one-way speed of light, and even the definition is an assumption based on the two-way speed

Since the one-way speed is impossible to measure can we just define it to be half of the two-way speed? There's no way to tell if that's correct or not but it makes no difference in any measurements you could make. So maybe for convenience we can just choose the one-way speed to be half the two way speed to simplify the calculations.

That's exactly what's done most of the time, but it should be noted that it's convention and assumption.

Re: New superconductor microprocessor yields a substantial boost in efficiency

#178

Post by KirillPanov »

The problem is the capital cost of the cryocooler.

The upfront costs of a cryocooler, spread out over the usable lifetime of the cryocooler (they're mechanical, they wear out), vastly exceeds the cost of electricity you save by switching from CMOS to JJs. Yes, I did the math on this. And cryocoolers are not following Moore's Law. Incredibly, they're actually becoming slightly more expensive over time after accounting for inflation. There was a LANL report about this which I'm trying to find, will edit when I find it. The report speculated that it had to do with raw materials depletion.

All of the above I'm quite certain of. I suspect (but am in no way certain) that the energy expended to manufacture a cryocooler also vastly exceeds the energy saved over its expected lifetime as a result of its use. That's just conjecture however, but nobody ever seems to address that point.

Re: New superconductor microprocessor yields a substantial boost in efficiency

#179

Post by jjcm »

MertsA wrote: post #163
fastball wrote: post #51

Earlier quoted context omitted.

Seems like it would be much harder to keep a stacked CPU superconducting as heat dissipation would be more difficult.

If you went a bit colder you could use superfluid helium and laser cut microchannels through the whole die. You would need to cool it to 2K and every degree at that temp is a fight but once past the transition point it becomes a remarkable thermal conductor and loses all viscosity. It seeps through tiny pores in porcelain like it's a sponge.

Solid idea, but the same thing that makes it work is what makes it impractical. Helium is almost impossible to contain long term, and would have to be replenished regularly.

Re: New superconductor microprocessor yields a substantial boost in efficiency

#180

Post by qayxc »

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?

This is an area that's still in its early stage, but yes, it would seem so.

Modules that are a few kilobytes in size have already been tested.

Even taking cryogenic operation into account, memory of this type consumes 10-100x less power than CMOS technology at roughly the same clock speed [1]

This is a very active field of research and there's a plethora of different approaches.

My guess is that 20 years from now there could be three types of computing:

• cryogenic quantum-computing for specialised tasks

• cryogenic ultra-high-performance computing

• high temperature computing (traditional CMOS-based)

with the first two not being available to consumers or small companies. Maybe it's going to be like in the 1970s and early 1980s when mainframes ruled supreme and you would rent these machines or compute time thereon.

People are accustomed to "the cloud" already, so it's not really a regression going back to centralised computing for a bit.

[1] https://www.researchgate.net/publication/320891331_Experimen...

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