Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Superconducting Microprocessors? Turns Out They're Ultra-Efficient (2021)

spectrum.ieee.org

Post reply on HN
Print view View original

51–60 of 100 posts

Re: Superconducting Microprocessors? Turns Out They're Ultra-Efficient (2021)

#51

Post by tliltocatl »

JumpCrisscross wrote: post #6
Terr_ wrote: post #3

Earlier quoted context omitted.

So someone else needs to prove a negative, that there exists no possible technology that will "disrupt" cryocoolers by bringing them to an unspecified price/performance point by an unspecified time in the future to service an unspecified computing use-case? That seems more than a little unfair. :p

> someone else needs to prove a negative, that there exists no possible technology that will "disrupt" cryocoolers Look at the Wikipedia references for crycoolers [1]. Note the dates and volume. Now look at room-tempuerature superconductors [2]. 1990 vs 2023. 5 vs 57. OP is arguing that a greater fraction of high-temperature superconducting research dollars might find purchase in improving the cryocooler than we pres…

The problem is, cryocooler theory is pretty well established and "solved at this point, so there is no reason to expect something completely new phenomena there, just some engineering improvements. Solid-state physics, on the other hand, is just computationally infeasible to "solve", so there is a plenty of possibility to discover something unpredicted.

Re: Superconducting Microprocessors? Turns Out They're Ultra-Efficient (2021)

#52

Post by canadianfella »

Strilanc wrote: post #44
AnthonyMouse wrote: post #34

Earlier quoted context omitted.

Wait, so does this imply (ignoring the time requirements) that you could do NP calculations with a feasible amount of energy , because the inputs and outputs are small? Combine that with something that uses time dilation to make it go fast (from our frame of reference) and you'd be giving even hypothetical quantum computers a silver medal.

Not unless you can isolate the computer from environmental noise exponentially well. Otherwise you'll need to spend exponential energy on entropy removal / error correction (e.g. keeping the dilution fridge running).

[dead]

Re: Superconducting Microprocessors? Turns Out They're Ultra-Efficient (2021)

#53

Post by philipswood »

AnthonyMouse wrote: post #34
philipswood wrote: post #25

Earlier quoted context omitted.

Energy is expended when you zero or set a bit. If you compute reversibly you need use special logic gates to not throw any bits away during the computation, like the Toffoli gate. All your operations need to have the same number of input and output bits and needs to be able to run forwards and backwards. Effectively you set or zero no bits during the entire computation that can't be losslessly reversed. If you struct…

Wait, so does this imply (ignoring the time requirements) that you could do NP calculations with a feasible amount of energy , because the inputs and outputs are small? Combine that with something that uses time dilation to make it go fast (from our frame of reference) and you'd be giving even hypothetical quantum computers a silver medal.

I think a longer runtime for a terminating program will require more state to be kept. Every step needs to keep extra reversibility information.

So I don't think this gives any edge on NP.

I suspect that even if you waited for the universe to cool down a lot by waiting aeons and then performed computations arbitrarily slowly you'd still be limited by your starting energy (maximum bits you can write to start with).

Although maybe using random bits might help somehow?

Re: Superconducting Microprocessors? Turns Out They're Ultra-Efficient (2021)

#54

Post by actinium226 »

timschmidt wrote: post #42
est31 wrote: post #37

According to the paper, their demonstration chip MANA has 21k of JJ units, which according to their estimates correspond to around 5k transistors. To compare, a single Nvidia GA100 has 54 * 10^9 transistors.

Some versions of the venerable MOS Technologies 6502 have only 3,218 transistors. The Intel 8080 has somewhere between 4,500 and 6,000. 5k transistors is square in the middle of "plenty for a classic 8 bit micro". Enough to run a basic *nix or embedded RTOS.

There's something I'm missing, they say the prototype hits 2.5 GHz, how is that possible if they only have the equivalent of 5k transistors? Or is clock cycle independent of transistor count?

Re: Superconducting Microprocessors? Turns Out They're Ultra-Efficient (2021)

#55

Post by actinium226 »

tuatoru wrote: post #21
hn72774 wrote: post #11

Earlier quoted context omitted.

Are you referring to the hardware cost vs operating cost? Or how the units are financed?

capex = capital expenditure; opex = operational expenditure. There's some theorem about investments that says it doesn't matter how they are financed. A good one is good, and a bad one is bad, whether or not you use debt.

I'll bet you I can find a way to finance a good deal that turns it into a bad one. The other way around seems harder.

Re: Superconducting Microprocessors? Turns Out They're Ultra-Efficient (2021)

#56

Post by g15jv2dp »

actinium226 wrote: post #54
timschmidt wrote: post #42

Earlier quoted context omitted.

Some versions of the venerable MOS Technologies 6502 have only 3,218 transistors. The Intel 8080 has somewhere between 4,500 and 6,000. 5k transistors is square in the middle of "plenty for a classic 8 bit micro". Enough to run a basic *nix or embedded RTOS.

There's something I'm missing, they say the prototype hits 2.5 GHz, how is that possible if they only have the equivalent of 5k transistors? Or is clock cycle independent of transistor count?

It depends on what you have your transistors do. You could even have one single transistor that you switch on/off very very quickly. You'd need to find a transistor with sub-ns switching time to reach >1GHz. It's not a very interesting "computation," though.

Re: Superconducting Microprocessors? Turns Out They're Ultra-Efficient (2021)

#58

Post by johntb86 »

actinium226 wrote: post #54
timschmidt wrote: post #42

Earlier quoted context omitted.

Some versions of the venerable MOS Technologies 6502 have only 3,218 transistors. The Intel 8080 has somewhere between 4,500 and 6,000. 5k transistors is square in the middle of "plenty for a classic 8 bit micro". Enough to run a basic *nix or embedded RTOS.

There's something I'm missing, they say the prototype hits 2.5 GHz, how is that possible if they only have the equivalent of 5k transistors? Or is clock cycle independent of transistor count?

Adding more transistors doesn't make your clock got faster, and it doesn't increase the speed of an individual transistor. The reason computers got both more transistors and faster in the past was that the transistors were continually shrinking; for a traditional MOSFET, Dennard scaling means that the smaller the transistor (and therefore the smaller its capacitance and voltage), the faster it switches. This device doesn't use MOSFET technology, so its scaling rules are different.

Re: Superconducting Microprocessors? Turns Out They're Ultra-Efficient (2021)

#60

Post by mlhpdx »

sigmoid10 wrote: post #38
BenoitP wrote: post #36

This is the future. As we try to go 3D and start stacking dies, the limiting factor of heat is getting even more blocking. It's not about consuming less electricity. It's about dissipating less of it as heat inside the microprocessor. The future will made of tiny porous cubes that are tall sandwiches of RAM and CPU/GPU/etc

Superconductivity with current materials is hard. Allost always because of the cooling. You can't just fabricate a porous cube of transistors and put it in a liquid helium ice bath. You need to have excess heat flowing out in a stable and predictable way. Otherwise once the center reaches critical temperature, the whole thing will explode. There's a reason why everyone is desperately searching for room temp low press…

Totally true, but it’s interesting that this technology lends itself to incremental improvements. And those improvements can be driven both from the hardware side and the software side. It seems like a virtuous cycle driving this to economic viability and optimization is possible. I’m no expert, though, so this is strictly my imagination.
Post reply on HN