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New superconductor microprocessor yields a substantial boost in efficiency
- klysm 6y agoUntil you account for the energy required to get it that cold
- thatcherc 6y agoSubtitle from the link: > The 2.5 GHz prototype uses 80 times less energy than its semiconductor counterpart, even accounting for cooling (emphasis mine)
- amelius 6y agoYeah, but only at datacenter scales. > Since the MANA microprocessor requires liquid helium-level temperatures, it’s better suited for large-scale computing infrastructures like data centers and supercomputers, where cryogenic cooling systems could be used.
- alkylketone 6y agoI'd be curious what the energy savings are like at smaller scales -- 80x at data center scales, but how about for a smaller machine, like a PC with phase cooling?
- nullc 6y agoI would expect the cooling to have a scaling advantage-- heat gain is proportional to surface area, but the mount of superconducting mojo you can use is proportional to volume so it should be more energy efficient to build larger devices.
- thatcherc 6y agoThe authors' power comparison is outlined in Section VI of their paper [0] (page 11-12). You might be able to figure out some intermediate scalings from that! [0] - https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=9295318 https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=929...
- ernst_klim 6y agoSo great for big computing centres and such? CERN and other should be happy with it.
- lallysingh 6y agoDC scale is great. Most stuff runs in a DC. What's wrong about requiring DC scale?
- nicoburns 6y agoHuh, this seemed a bit too good to be true on first reading. But given that the limits on computing power tend to thermal, and that a superconducting computer presumably wouldn't produce any heat at all, it does kind of make sense.
- ska 6y agoThe system as a whole will produce heat, but less.
- nicoburns 6y agoTrue, but usually the problem is removing the heat from the chip, not the total amount of heat produced. If the heat is mostly produced by the cooling system then that problem all but goes away.
- ska 6y agoNot really at data centre scale. Heat directly in the CPU is a limiting factor on how fast an individual chip can go, and at the board level is an issue of getting heat away from the CPU somehow. But that heat has to go somewhere. When you have rooms full of them the power and cooling issues become key in a way that doesn't matter when it's just a PC in your room.
- mensetmanusman 6y agoAny entropy reduction activity in one area automatically means a lot more heat is added somewhere else :) (2nd law)
- b0rsuk 6y agoGiven the cooling requirements, I suppose it would create completely impassable rift between datacenter computing and other kinds. Imagine how programming and operating systems might look in a world where processing power is 80x cheaper. Considering that "data centers alone consume 2% of world's enegy", I think it's worth it.
- layoutIfNeeded 6y ago>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.
- systemvoltage 6y agoJavascript emulator in Javascript!
- dmingod666 6y agoDo you mean the "eval()" function?
- tsimionescu 6y agoNo, they mean writing the eval () function in pure JavaScript.
- dmingod666 6y agoWow
- lkbm 6y agoGary Bernhardt's presentation on the "history" of Javascript from 1995 to 2035 is hilarious and seems like something you'd enjoy: https://www.destroyallsoftware.com/talks/the-birth-and-death-of-javascript https://www.destroyallsoftware.com/talks/the-birth-and-death... It takes things way beyond simply "emulating Javascript in Javascript", yet is presented so well that you barely notice the transition from current (2014) reality to a comically absurd future.
- px43 6y agoIt'll be interesting to see if the cryptocurrency mining industry will help subsidize this work, since their primary edge is power/performance. During stable price periods, the power/performance of cryptocurrency miners runs right up to the edge of profitability, so someone who can come in at 20% under that would have a SIGNIFICANT advantage.
- wmf 6y agoIn this paper, we study the use of superconducting technology to build an accelerator for SHA-256 engines commonly used in Bitcoin mining applications. We show that merely porting existing CMOS-based accelerator to superconducting technology provides 10.6X improvement in energy efficiency. https://arxiv.org/abs/1902.04641 https://arxiv.org/abs/1902.04641
- reasonabl_human 6y agoLooks like the admit it’s not scalable and only applies to workloads that are compute heavy, but a 46x increase over cmos when redesigning with an eye for superconducting env optimizations
- Badfood 6y agoCost / hash. If power is free they don't care about power
- adolph 6y ago/ time. Time is immutable cost.
- gwern 6y agoEven if power is free, you still get only a limited amount of it to turn into hashes. Power sources like plants or dams only produce so much. Even if you have bribed a corrupt grid operator to give you 100% of the output from a X megawatt coal plant for free, you're still limited to X megawatts of hashing. If you can turn that X megawatts into 10*X megawatts' worth of your competitors' hashing, well, you just 10xed your profit.
- jcfrei 6y agoDoes superconductivity remove or reduce the limit on die size?
- undersuit 6y agoI'm making a naive guess here. No, superconducting transistors are probably harder to create than non super conducting transistors so the limits on die size from defects are even more pronounced and superconducting doesn't change the speed of light for electrons on the chip so it doesn't change the timing issues arising from large dies.
- akiselev 6y agoThe limits on die size for the competitive consumer chip market are nothing like that of the B2B market. Largest chip ever made was over 40,000 mm^2 [1] compared to Intel's 10900K at ~205 mm^2. In production mainframe chips like IBM's Z15s are on the order of 700mm^2. The fab process has a lot of levers so very low defect rates are possible but not at the scale of a consumer CPU. [1] https://techcrunch.com/2019/08/19/the-five-technical-challenges-cerebras-overcame-in-building-the-first-trillion-transistor-chip/?utm_campaign=fullarticle&utm_medium=referral&utm_source=inshorts https://techcrunch.com/2019/08/19/the-five-technical-challen... Edit: I assume a supercoducting microprocessor would use a strategy similar to the AI monolith in [1]. Just fuse off and route around errors on a contiguous wafer and distribute the computation to exploit the dark zones for heat dissipation.
- qayxc 6y agoIf implemented using switches based on the Josephson effect like here, then no. The thickness of the required insulating barrier presents a hard lower limit to the structure size. The actual value of that limit depends on the material used and the particular implementation of the Josephson junction, of which there seems to be quite a few. So the limit depends on how thin the barrier can be made.
- sliken 6y agoCan't imagine why it would, but the lack of heat makes a 3D cpu much more feasible. So you could take 20 die, make 20 layers, and get radically more transistors per volume.
- the8472 6y ago> 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.
- freeqaz 6y agoMind expanding on this a bit more? What is that that limit and how does it relate to the clock speed?
- the8472 6y agohttps://en.wikipedia.org/wiki/Landauer%27s_principle https://en.wikipedia.org/wiki/Landauer%27s_principle Note that the gates themselves used here are reversible, so the limit shouldn't apply to them. But the circuits built from them them aren't reversible as far as I can see in the paper, so it would still apply to the overall computation.
- Enginerrrd 6y agoIt's not about clock speed per se. It's about the lowest possible energy expenditure to erase one bit of information (or irreversibly destroy it by performing a logical operation). The principle comes about from reasoning about entropy loss in said situations. There's a hypothesized fundamental connection between information and entropy manifest in physical law. The idea is that if you destroy one possible state of a system, you have reduced the entropy of that system, so the 2nd law of thermodynamics implies that you must increase the entropy of the universe somewhere else by at least that amount. This can be used to say how much energy the process must take as soon as you choose a particular temperature. This applies to any irreversible computation. IMO, The fact that it's only 38x the minimum is MIND BLOWING.
- jcims 6y agoIs there an idea of entropic potential energy/gradient/pressure? Could you differentiate encrypted data from noise by testing how much energy it requires to flip a bit?
- laurent92 6y agoThis could explain the extreme push to the Cloud, for example with Atlassian who discontinues its Server products entirely, and only keeps Data Center or Cloud versions. It behaves as if personal computing or server rooms in companies won’t be a thing in 2025.
- lallysingh 6y agoThis sounds perfect for space. It's cold in space, power is at a premium, and it can be tough getting rid of heat.
- vincnetas 6y agoIts a bit cold in space. But actually its really difficult to cool down things in space as there is nothing around you to transfer heat to.
- TOMDM 6y agoI'm ignorant of the specific physics, but what if you got it cold before you sent it into a vacuum, and then shielded it from external radiation? Surely due to the massively reduced power usage it would be easier to keep it cool relative to traditional compute
- fastball 6y agoThe problem is that the act of computation is generating heat, so you can't just insulate your superconducting CPU, you need a way to dissipate the heat it must generate (this applies to all irreversible computations). This is difficult, because the only way to dissipate heat in space is radiation (with conduction usually acting as a middleman), which is constrained by the surface area of your radiator. So no, it probably wouldn't be any easier in space.
- akiselev 6y agoIdeally this server farm would attach to a giant rock somewhere in a stable orbit and drill heat exchange pipes deep into the rock, like how we do for geothermal energy here on earth but in reverse. This whole exercise would require a nuclear reactor to be feasible both economically and engineering wise.
- cbozeman 6y agoMass Effect taught me this. I miss old school BioWare.
- VanillaCafe 6y agoIf it ever gets to home computing, it will get to data center computing far sooner. What does a world look like where data center computing is roughly 100x cheaper than home computing?
- whatshisface 6y agoIt will look like the 1970s.
- cbozeman 6y agoDumb terminals everywhere. A huge upgrade of high-speed infrastructure across the US since everyone will need high throughput and low latency. Subscriptions will arise first, as people fucking love predictable monthly revenue - and by people I mean vulture capitalists, and to a lesser degree, risk-averse entrepreneurs (which is almost an oxymoron...), both of whom you can see I hold in low regard. Get ready for a "$39.99 mo. Office Productivity / Streaming / Web browsing" package", a "$59.99 PrO gAmEr package", and God knows what other kinds of disgusting segmentation. Someone, somewhere, will adopt a Ting-type model where you pay for your compute per cycle, or per trillion cycles or whatever, with a small connection fee per month. It'll be broken down into some kind of easy-to-understand gibberish bullshit for the normies. In short, it'll create another circle of Hell for everyone - at least initially.
- f1refly 6y agoI really appreciate your pessimistic worldview, keep it up!
- cbozeman 6y agoI basically just base my worldview on the fact that everyone is ultimately self-serving and selfish. Hasn't failed me yet. :)
- colinmhayes 6y agoThe great thing about capitalism is that it replaces bad services with good ones. Only exceptions are natural monopolies that the state fails to regulate, which datacenters are not.
- zelienople 6y agoThe other strategy that is ultra-efficient is to stop using the net to sell hoards of useless crap that will break the day after the warranty expires and cannot be repaired. That would save money on the computing power as well as the mining, transportation of raw materials, refining, transportation of refined materials, manufacturing, transportation of finished goods and the whole retail chain. Unless we achieve room-temperature semiconducting processors, this will only benefit data centres, most of whose power is used to sell stuff. Does anyone actually think that the savings will be passed on to the consumer or that business won't immediately eat up the savings by using eighty times more processing power? Hey, now we can do eighty times more marketing for the same price!
- jkaptur 6y agoCouldn't you say this about virtually any hardware improvement?
- superkuh 6y agoSure. But how efficient are they once you include the power used to keep them cold enough to superconduct? I doubt that they're even as efficient as a normal microprocessor would be.
- SirYandi 6y ago“But even when taking this cooling overhead into account,” says Ayala, “The AQFP is still about 80 times more energy-efficient when compared to the state-of-the-art semiconductor electronic device, [such as] 7-nm FinFET, available today.”
- inglor_cz 6y agoNice, 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.
- gnulinux 6y agoIf the throughput is fast enough 3+3=6 seconds latency doesn't really sound that bad. There are websites with that kind of lag. You can't use to build a chat app, but you can use it as a cloud for general computing.
- inglor_cz 6y agoYes, for general computing, that would be feasible.
- mindvirus 6y agoFun 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 https://en.m.wikipedia.org/wiki/One-way_speed_of_light
- faeyanpiraat 6y agoThere 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 https://www.youtube.com/watch?v=pTn6Ewhb27k
- physicles 6y agoYes! 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.
- wmf 6y agoInteresting tradeoff: AQFP logic operates adiabatically which limits the clock rate to around 10 GHz in order to remain in the adiabatic regime. The SFQ logic families are non-adiabatic, which means they are capable of running at extremely fast clock rates as high as 770 GHz at the cost of much higher switching energy.
- hikerclimb 6y agoHopefully this doesn’t work
- Symmetry 6y agoHmm, I wonder what the feature size is and whether they'd have a good story about storage at commensurate low power usage?
- andrelaszlo 6y agoNot a physicist so I'm probably getting different concepts mixed up, but maybe someone could explain: > in principle, energy is not gained or lost from the system during the computing process Landauer's principle (from Wikipedia): > any logically irreversible manipulation of information, such as the erasure of a bit or the merging of two computation paths, must be accompanied by a corresponding entropy increase in non-information-bearing degrees of freedom of the information-processing apparatus or its environment Where is this information going, inside of the processor, if it's not turned into heat?
- abdullahkhalids 6y agoIf your computational gates are reversible [1], then in principle, energy is not converted to heat during the computational process, only interconverted between other forms. So, in principle, when you reverse the computation, you recover the entire energy you input into the system. However, in order to read out the output of computation, or to clear your register to prepare for new computation, you do generate heat energy and that is Landauer's principle. In other words, you can run a reversible computer back and forth and do as many computations as you want (imagine a perfect ball bouncing in a frictionless environment), as long as you don't read out the results of your computation. [1] NOT gate is reversible, and you can create reversible versions of AND and OR by adding some wires to store the input.
- aqme28 6y agoI was curious about this too. This chip is using adiabatic computing, which means your computations are reversible and therefore don't necessarily generate heat. I'm having trouble interpreting what exactly that means though.
- patagurbon 6y agoBut you have to save lots of undesirable info in order to maintain the reversibility right? Once you delete that don't you lose the efficiency gains?
- 6y ago
- tromp 6y agoThis 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?
- faeyanpiraat 6y agoIf 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)
- qayxc 6y agoCryogenic memory can be orders of magnitude more efficient than traditional RAM, even taking the cooling into account.
- qayxc 6y agoThis 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_Experimental_Demonstration_of_a_Josephson_Magnetic_Memory_Cell_with_a_Programmable_p-Junction https://www.researchgate.net/publication/320891331_Experimen...
- m3kw9 6y agoWhat about the energy that is needed to cool this thing?
- tgbugs 6y agoSignificantly less the the energy it takes to cool current processors. Nearly five years ago I was talking to a professor who was at a conference on the future of computing and there were folks there from the big 5 and he said that all of them had done the math on how much it cost to run their data centers vs run the cooling for cryogenic super conducting computers, and they all concluded that it was vastly cheaper to run at cryogenic temperatures, at least in part because they would drop the cost of running the cpus essentially to zero because they would all be superconducting.
- adamredwoods 6y agoThis article I found is a bit more revealing in the technology summary for those interested. https://cacm.acm.org/news/232327-the-outlook-for-superconducting-computers/fulltext https://cacm.acm.org/news/232327-the-outlook-for-superconduc...
- KirillPanov 6y agoThe 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.
- peter_d_sherman 6y ago"Everything becomes a superconductor -- when you put enough voltage through it..." [1] <g> Footnotes: [1] Including non-conductors... but you need a lot of voltage! <g>
- aqfp 6y agoI'm one of the authors of the published paper that IEEE Spectrum referred to in the post. First off, thanks for posting! We're so delighted to see our work garner general interest! A few friends and relatives of mine mentioned that they came across my work by chance on Hacker News. I already noticed the excellent questions and excellent responses already provided by the community. This comment might get buried but I'd just like to mention a few things: - Indeed, we took into account the additional energy cost of cooling in the "80x" advantage quoted in the article. This is based on a cryocooling efficiency of 1000 W at room temperature per Watt dissipated at cryotemps (4.2 Kelvin). This 1000W/W coefficient is commonly used in the superconductor electronics field. The switching energy of 1.4 zJ per device is quite close to the Landauer limit as mentioned in the comments but this assumes a 4.2 K environment. With cryocooling, the 1000x factor brings it to 1.4 aJ per device. Still not bad compared to SOTA FinFETs (~80x advantage) and we believe we can go even lower with improvement in our technology as well as cryocooling technology. The tables in Section VI of the published paper (open-access btw) goes on to estimate what a supercomputer using our devices might look like using helium referigeration systems commercially available today (which have an even more efficient ~400W/W cooling efficiency). The conclusion: we may easily surpass the US Department of Energy's exascale computing initiative goal of 1 exaFLOPS within a 20-MW power budget, some thing that's been difficult using current tech (although HP/AMD's El Capitan may finally get there, we may be 1-2 orders of magnitude better assuming a similar architecture). - Quantum computers require very very low temps (0.015 K for IBM vs the 9.3 K for niobium in our devices). With the surge in superconductor-based quantum computing research, we expect new developments in cryocooling tech which would be very helpful for us to reduce the "plug-in" power. - Our circuits are adiabatic but they're not ideal devices hence we still dissipate a tiny bit of energy. We have ideas to reduce the energy even further through logically and physically reversible computation. The trade-off is more circuit area overhead and generation of "garbage" bits that we have to deal with. - The study featured only a prototype microprocessor and the main goal was to demonstrate that these AQFP devices can indeed do computation (processing and storage). Through the experience of developing this chip, it helped revealed the practical challenges in scaling up, and our new research directions are aggressively targetting them. - The circuits are also suitable for the "classical" portion of quantum computing as the controller electronics. The advantage here is we can do classical processing close to the quantum computer chip which can help reduce the cable clutter going in/out of the cryocooling system. The very low-energy dissipation makes it less likely to disturb the qubits as well. - We also have ideas on how to use the devices to build artificial neurons for AI hardware, and how we can implement hashing accelerators for cryptoprocessing/blockchain. (all in the very early stages) - Other superconductor electronics showed super fast 700+ GHz gates but the power consumption is through the roof even before taking into account cooling. There are other "SOTA" superconductor chips showing more Josephson junction devices on a chip... many of those are just really long shift-registers that don't do any meaningful computation (useful for yield evaluation though) and don't have the labyrinth of interconnects that a microprocessor has. - There are many pieces to think about: physics, IC fabrication, analog/digital design, architecture, etc. to make this commercially viable. At the end of the day, we're still working on the tech and trying to improve it, and we hope this study is just the beginning of some thing exciting.