15 ms·

Aging Problems at 5nm and Below

• teruakohatu 6y ago
  It would be unfortunate if future process improvements resulted in fragile CPUs and GPUs. I can sort of imagine Nvidia rubbing their hands with glee at the prospect of non-overclocked GPUs aging prematurely, killing used sales and forcing data centers to upgrade to more expensive compute cards.
  • fouc 6y ago
    I think that professional tier hardware generally comes with some sort of guarantees on how long they last, so data centers shouldn't be affected much.
    • teruakohatu 6y ago
      There is a market for used cards. It is one way to get a relatively slow but high RAM compute card without paying extreme prices. Killing that market would force a lot of non-corporate users to start coughing up for extremely expensive new hardware.
    • me_me_me 6y ago
      Thats correct. And it makes sense. If you buying HW in bulk, you take into account how much power it will draw, what's the expected life expectancy, how much work will given part do and not just the price. If you get an amazing price for part that fails often, it might cost you way more in long run.
      • Dylan16807 6y ago
        In general I would expect a bulk purchaser to be less sensitive to failure. If I'm buying one drive or CPU, I might pay a premium to drop the failure rate from 4% to 1%. If I'm buying dozens to hook together in a fault-tolerant system, I'll go for the cheap one and buy a few extras.
        • me_me_me 6y ago
          When you buy 1000 CPU the failure rate of 4% every year. That gives you statistically 40 dead servers each year for 5 years (avg component guaranteed life). thats 200 dead cpus. Lets say $1000 per cpu thats $1,000,000 cost and $200,000 loss to damage. 1% - 50 dead CPU in 5 years - $50,000 in losses In this scenario you have $150,000 to save or spend to get better equipment. Also an important note. On top of that you suffer downtime losses and manpower cost of taking server out and swapping parts. If your eCommerce goes offline that might cause significant monetary loss. For any large scale purchases its all about the numbers game. In case of single purchases. Paying extra to get form 4% to 1% seems excessive (depending on the cost increase). At this percentage levels its a roll of dice if it dies or not.
          • Dylan16807 6y ago
            That wasn't supposed to be a per year failure rate. 20% per 5 years is a crazy amount. Divide the numbers by 5 to get a per-year failure closer to my intent. So if it's $850 for the 4% failure chip, and $1000 for the 1% failure chip, I'll probably buy the cheaper one in bulk. $850k upfront and $34k in replacement, vs. $1000k upfront and $10k in replacement. There's extra manpower, sure, but even if it costs a hundred dollars of labor per replacement the numbers barely budge. > downtime losses In a big system you shouldn't have those from a single server failure! Downtime losses are the point I was making. As someone buying just one drive or chip, failure costs me massive amounts beyond the part itself. But if I can buy enough for redundancy, then those problems become much much smaller. If you're running things off one server, then apply the single device analysis, not the bulk analysis.
    • blaser-waffle 6y ago
      Most of the pro grade hardware does come with those assurances, usually with support and replacement contracts as well. And make no mistake, they may replace things a lot -- at my old gig we had a lot of visits from Dell. To Dell's credit, we had a LOT of gear to cover, in several different colo spaces. Point is though, they price the cost of replacement into those guarantees. Doesn't mean the hardware will last longer, just that support & replacements are
  • LordHeini 6y ago
    Lets say they could get away with it. What would be a reasonable time span for this? Maybe 5 years? I have a gtx970 in my pc which is 5 years old by now. While the card is fine by itself, it is too slow and thus getting replaced in the near future and moved into an office pc. But which data center uses 5 year old graphics cards? It is save to assume that dedicated compute card gets replaced from time to time anyway. Moores law is still too strong.
    • 0-_-0 6y ago
      > What would be a reasonable time span for this? The strong temperature depencence means this will likely look like "5 years with low fan noise and 30 years with high fan noise"
    • close04 6y ago
      A 5-10 year old machine can still be perfectly usable. I have a 2012 laptop with a high end i7 3-series CPU, high end Quadro GPU and I would hate if any of them failed because it's not something I can easily (if at all) fix, the whole laptop would become a doorstop. An i7 6700 is already 5 years old. That's most certainly not an outdated "can throw away" CPU. Neither will a 3rd gen. Ryzen 4 years from now.
    • Reelin 6y ago
      I'm typing this from a ~6 year old laptop (used as a desktop OFC) for example. My phone is ~5 years old (unbelievable, I know). When it fails in a few years I'll happily buy a "new" ~4 year old refurbished phone again. Regarding Moore's law, there's only so many possible shrinks left to go. Once we hit that wall the incentive to be on the latest node is significantly reduced. Combine that with associated lifetime reductions and I think larger nodes might even end up preferable in many cases.
    • iforgotpassword 6y ago
      Don't forget preservation efforts. I know most people don't care about it but many enthusiasts like giving old systems a spin every now and then. You can still build your dream 386 from used parts off of eBay and play wing commander on a CRT. For the upcoming generation of hardware that might just be impossible then.
  • 0-_-0 6y ago
    Since the wear is exponentially dependent on temperature, better cooling (e.g. water cooling) could extend the life of chips significantly, so if someone is worried about chip ageing from continuous use they can just install a water cooler, which is less pricey than an enterprise card.
    • AlanSE 6y ago
      Good point, but not for laptops and devices though.
    • dmos62 6y ago
      Maybe industrial water cooling has a better track record, but consumer water cooling is an extremely fiddly and expensive process. My main source is Linus Tech Tips. Unless you're willing to spend a lot of money and effort, air cooling is more effective and much much cheaper. Simple (small) water cooling solutions tend to not perform better than air cooling. Plus, water cooling requires a lot of maintenance, because it's more complex (e.g. there's pumps that can fail) and because the cooling liquid can get contaminated and cause cooling performance to drop. I can see how it could be cheaper to use cheap air cooling on the chips and efficient, central room cooling.
      • ncrmro 6y ago
        The day I had to top up my computers water.. I went back to air.
        • raxxorrax 6y ago
          Spilled some coffee in my open computer case once. Wasn't running faster at all... But seriously, I think it would be a viable solution for server farms, but it didn't really catch on there yet. Probably still a matter of price. There are some theoretical application with heat exchangers though. If we could recycle some of that, computing would be much more efficient in general.
          • Dylan16807 6y ago
• lnsru 6y ago
  Dream of cellphone manufacturers. Phone dies beyond repair right after 2 year contract. What can be better!? Edit: my wife still uses iPhone 6, I recently build dedicated Linux machine with my 8 year old FX-8350 CPU with ancient mainboard. The world with disposable electronics is closer and closer. I bet, exact lifetime can be precisely simulated with software from the companies mentioned in the article.
  • smolder 6y ago
    The world of disposable electronics is definitely something we would be moving away from if we were smart enough to cooperate a bit as a species. We should be managing complete product life cycles for the best efficiency by way of recycling, reuse, durable designs, etc.
  • ChuckNorris89 6y ago
    I feel you and it's not really a reason to throw it away, but that FX CPU uses more power than modern CPUs for similar performance. I also like my old car and I'll keep it as long as I can but I'm aware a new one would be much more fuel efficient.
    • Marsymars 6y ago
      > I also like my old car and I'll keep it as long as I can but I'm aware a new one would be much more fuel efficient. From what I see of comparable-model cars, efficiency gains in engines, aerodynamics, etc. have mostly been offset by safety, emissions, and QoL improvements that have increased weight. For instance, by spec, the most fuel-efficient Corolla was a 1984 model.
      • willis936 6y ago
        I am skeptical of that last sentence. Do you have a source?
        • jtbayly 6y ago
          If you disqualify hybrids and allow diesels... https://www.fueleconomy.gov/feg/PowerSearch.do?action=noform&path=1&year1=1984&year2=2020&make=Toyota&baseModel=Corolla&srchtyp=ymm https://www.fueleconomy.gov/feg/PowerSearch.do?action=noform... But the weight difference is also substantial between 1984 and 2020 models: 2110 lbs vs 2910 lbs
• tlb 6y ago
  For a few applications, like compiling and training, I would be overjoyed to buy a CPU that was 50% faster, but only lasted 18 months. But for most, I care a lot more about lifetime. It'll be interesting if this ends up being one of the major trade-off axes, along with power and cost.
  • chime 6y ago
    I would gladly pay 100k+ for a single 10ghz processor with comparable bus speed / RAM combo. Got a single threaded legacy DB that runs way too many things for a large company. Upgrading to a new system is going to cost million+. Running liquid cooled 5hz CPU on a gaming rig right now with an identical box on standby in case of H/W issues. Could easily justify spending 200k every year if it doubled the DB performance.
    • DaiPlusPlus 6y ago
      Wouldn’t it cost less than $100k to fix the project to use any commodity SQL database (presumably over ODBC)? Or are we talking about an unsalvageable 4GL system that had its last update 15 years ago that does everything (storage engine, OLTP, forms UI framework, security, and reports)?
      • chime 6y ago
        Close. Running 2009 version of a commercial DB that does everything with no cheap upgrade path.
        • DaiPlusPlus 6y ago
          It’s Progress or FoxPro, right?
    • ksec 6y ago
      This. In terms of Single Core / Thread Performance we have reached the end of S curve. We haven't had much IPC improvements since Skylake in 2014. We reached the Max Clock speed per normal Cooling possibilities. Although current rumours suggest 7nm Ocean Cove coming in 2022 with 85% increase of IPC compared to Skylake. I wish we could also make performance node that push through 6Ghz.
• DavidSJ 6y ago
  “For example, microprocessor degradation may lead to lower performance, necessitating a slowdown, but not necessary failures. In mission-critical AI applications, such as ADAS, a sensor degradation may directly lead to AI failures and hence system failure.” This is probably a superficial analogy, but this made me think of people suffering from dementia in old age.
  • Taek 6y ago
    Dementia is actually a decent metaphor for what happens to an aging chip. Internally, a chip is extremely dependent on gate timings. As the chip decays, certain gates or wires will start to slow down or speed up, and the chip gets sloppier. Often, you can address the issue by slowing the chip clock rate down, because this gives you a much wider margin for error on your gate timings. Certain operations will be impacted sooner and more heavily than others. Eventually, the timings get bad enough that certain operations (or even the whole chip) just break altogether.
• threatripper 6y ago
  I would expect the problems to become both exponentially harder and exponentially more to solve as we scale down. But vice versa, using the process and knowledge we gain from 5 nm chips might improve the lifetime of 7 nm chips by orders of magnitude. And again using the 4/3/2 nm process knowledge we might obtain very durable 5 nm chips in a few years.
  • Causality1 6y ago
    Is there much of a market for medium-detail processes? We have the desktop/server/workstation/smartphone market using the very smallest detail processes, with maybe some categories using the previous-generation node. Then we have the embedded market which is everything from cheap-as-dirt 350nm microcontrollers to 28nm ARM chips. Nobody really wants the five-years-ago chips, the currently 18-22nm node. They're too expensive to buy by the million and not shiny enough to compete against the newest stuff.
    • ksec 6y ago
      There are plenty of market for in between 28nm to 12nm node. It is simply a natural progression between Cost, Features, Performance and Economics of Chips. Especially when they are the last few nodes before you move up to EUV. A10 / T2 used in many of the Apple Appliance are 16nm, along with dozens of WiFi, Modem, Ethernet Controller, ASIC / FPGA etc. These are easily 100M unit a year. As long as the cost benefits fits their volume they will move to next node.
    • hwillis 6y ago
      ASICs?
  • hwillis 6y ago
    > But vice versa, using the process and knowledge we gain from 5 nm chips might improve the lifetime of 7 nm chips by orders of magnitude Probably not. The problems at each scale are very different and tend not to have much overlap. Process limitations also exist regardless- say you figure out that patterning transistors at 3 nm increases lifetime in a way that is applicable to 7 nm. 7 nm still can't take advantage of it as long as it requires 3 nm scale patterning, if there is even overlapping technology. Even if it requires adding a new step, say a wafer treatment that is necessary at 3 nm but optional at 7 nm, the economic benefit from increased lifespan is probably not worth retooling the old equipment.
• etaioinshrdlu 6y ago
  How much redundancy do modern CPU chips have? If a single transistor goes bad in say, a cache area, is the CPU guaranteed to be a brick?
  • teruakohatu 6y ago
    I think the usual reply to that question is that it depends on which transistor. Not quite the same thing but there was a Raspberry Pi board on the homepage earlier today which has hacksawed in half and still worked, the person who did that has also cut some microprocessors in half successfully and they still work because they were cutting off bits he does not plan on using and which are not required for the rest of the device or chip to function. I am sure a AMD Ryzen CPU would work without a core or two. In fact they often disable cores before shipping by zapping a fuse. But if the same transistor on every core somehow blew, then you would probably be left with a dead CPU.
    • starky 6y ago
      To be fair, that guy who cut the RPi merely cut off the USB ports, RJ45 jack, and the ethernet controller and maybe a couple caps. I don't think chopping off a couple of low pin count peripherals far away from the SoC and DRAM counts as "cutting the board in half"
      • teruakohatu 6y ago
        I did say it wasn't exactly the same thing but at least with some previous *Lake Intel CPUs the gfx took up quite a lot of the die. If you are using an external GPU quite a lot of transistors could fail and you could still use the CPU, just like hacksawing off the ethernet chip.
  • lostmsu 6y ago
    My thoughts exactly. If a CPU could self-test reliably, and turn off parts of cache, cores, bus lines, etc. I don't think random failures would be a major problem. Of course it might be too expensive to design such a feature.
  • 6y ago
• Animats 6y ago
  “However, densely packed active devices with minimum safety margins are required to realize advanced functionality requirements. This makes them more susceptible to reliability issues caused by self-heating and increasing field strengths." We're going to have very short-lived electronics. The Ford EEC IV engine control unit from the mid-1980s was designed for a 30 year lifespan. Which it delivered. Can the industry even make 30-year parts any more? For automotive, a key issue may be to turn stuff off. All the way off. Vehicle lifespans are only around 6,000 hours of on time. But too much vehicle electronics runs even when the vehicle is off.
  • remotists 6y ago
    Shorter-lifespans mean more frequent sales. Phones used to last 6 years now they they are made and branded to be used for less than 2 years.
    • m12k 6y ago
      This seems to be a fundamental economics issue: Things are only valued when they are sold. It's much more profitable for companies to sell me the same thing over and over again every couple years, than to sell me something repairable that will last for decades. Most measures, like GDP, don't capture the inefficiency of this, because they don't capture the value of the things in my house that don't need to be replaced, they only capture the value of the new stuff I buy when the old crap breaks. I think this has many detrimental side effects: There's the opportunity cost, because the money I spend on planned obsolescence could have been spent on other products that added more value for me and the world. It wastes natural resources with more stuff ending up in landfills and CO2 ending up in the atmosphere to manufacture and ship the replacements. And finally it helps reinforce the need to work stressful jobs to have enough money to keep buying these things that keep breaking - it's harder to have 'enough' money. How do we as a society encourage products that last?
      • kwhitefoot 6y ago
        > How do we as a society encourage products that last? People are attracted to novelty. While you and I might value the old and functional things that we have and use everyday there is a substantial number of people who will get rid of things like toasters, food mixers, etc., simply because they don't match the colour scheme of the kitchen; the suppliers only care about those people, not us because we don't make any money for them. If you want products that last you will somehow have to moderate the human desire for novelty. I think that this could be done but it would mean dismantling our educational systems and replacing them with education in the old fashioned sense of producing people who can think and analyse, people who have a sense of history and an understanding of how the world came to be the way it is. But what use are such people to a society based on, not merely conspicuous, but also excessive consumption?
• rwmj 6y ago
  The article mentions in passing "high elevation (data servers in Mexico City)", but doesn't say why. Low air pressure because that makes cooling systems less efficient?
  • jfoutz 6y ago
    That stuck out to me as well. I kinda suspect more ambient radiation. Less atmosphere to catch stray particles, and the smaller gates are more susceptible. Smaller interactions cause random errors. Anyway, far far outside the scope of my expertise. But that's my guess.
    • m12k 6y ago
      I think you're right. I remember reading a 'bit flips can and do happen' war story about server crashes that only occurred at a client located at a high elevation.
      • nieve 6y ago
        NOAA has a supercomputing center in Boulder, CO that has produced some analysis of this, but if memory serves they also have to deal with some low intensity radiation from the Flatirons formation they're up by. Get enough computers with enough RAM and all bit flip sources start counting.
    • freeqaz 6y ago
      Could that actually effect the life of the chip though? Annoying to have your system crash, but that isn't a longevity problem by itself. Does a stray ray cause the gate to wear prematurely?
      • jfoutz 6y ago
        yeah. I've done a little bit (tiny, inconsequential, not an expert) with satellites. When cosmic rays have enough energy they'll move atoms around. That's bad for gates. A 486, old big gates, doesn't hurt much. maybe you have to reboot every few days. Tiny little 2 atom gates, they're more delicate. think plastic vs glass glassware. With plastic you can have a few incidents and it'll still be a glass. with glass, it's a lot easier to chip an edge or shatter and not be usable anymore. Again, not my area. But I suspect altitude is really bad for tiny systems because they lose so much "free" shielding.
• jokoon 6y ago
  It's weird that I've read so many people say "your computer isn't slow because of transistors degrading, but because of other thing like software/driver/OS stuff".
  • thebruce87m 6y ago
    As you as you mean “slower than it was” then that statement holds mostly true. Your CPU, RAM and GPU should perform the same on day 1 and day 10000 as long as they are still functional. Any “degradation” won’t make them slower, just non functional. The complication in this comes from the SSD, where the flash cells have a feedback loop for operations such as erasing that can take longer as these cells degrade.
    • jokoon 6y ago
      CPU have error correction, which will mitigate transistor aging and make the CPU work slowly instead of not at all. It will not "perform the same". At some point there is a noticeable slowdown, and even though Wirth's law is at work, it's not the entire story. Heat will also make any chip age faster. This article talks about aging under 5nm, but aging is already an issue above 5nm. Read the article. https://en.wikipedia.org/wiki/Electromigration#Practical_implications_of_electromigration https://en.wikipedia.org/wiki/Electromigration#Practical_imp... > The complication in this comes from the SSD I always experienced slowdowns on computer that did not have SSD. Software is not always the only problem.
      • rcxdude 6y ago
        Error correction in CPUs is generally limited to the cache, and its incidence is recorded: if something had failed permanently such that the error correction path was being taken constantly, you would be able to record it. Absent a mechanism which reduces the clock speed of the CPU when it becomes unstable, there's no reasonable way in which failures in the CPU will result in it running slower. Such a mechanism doesn't generally exist: modern CPUs regulate their clock but only in response to a fixed power and temperature envelope. The recent iphone throttling is the only notable case where anything was done automatically in response to an unstable CPU, and that consisted of applying a tighter envelope if the system reset. This is reflected in the experiences of those who run older hardware with contemporary software: it generally still works just fine at the speed that it used to.
• LargoLasskhyfv 6y ago
  So what? I look at the MTBF/TBW(terabytes written) of solid state disks and shrug. From a very zoomed out view(and a laymans at that!) the whole semiconductor industry seems like system gastronomy. While the few main players equal McDonalds and Burger King, there is only so much you can do with similar equipment arranged in the same ways. While I'm sure the two could produce the same things, if given access to the same ingredients, they aren't allowed to. Same for Coke vs. Pepsi. Anyways, if you want to have it different, then you either need different systems arranged in different ways processing different ingredients, or are stuck with wailing Oh vey! I'd rather prefer some cheering for alternatives like [1] https://duckduckgo.com/?q=Semefab+Wafertrain+Bizen+Searchforthenext https://duckduckgo.com/?q=Semefab+Wafertrain+Bizen+Searchfor... and [2] https://duckduckgo.com/?q=Yokogawa+minimal.fab https://duckduckgo.com/?q=Yokogawa+minimal.fab Oh YAY! That would at least enable the likes of KFC and Pizza Hut in comparison. And fizzly Bundaberg! Oy! edit: [3] http://www.besang.com/ http://www.besang.com/
• nullifidian 6y ago
  Always wanted to know if server cpus are of lower base/boost frequencies, compared to HEDT cpus, precisely because they are designed to work 24/7 at 100% load for a decade, while consumer grade cpus have looser reliability requirements and would fail in this regime at a high rate(without overclocking), so they allow for higher frequency, provided that it's not 24/7 100% load. The conventional explanation is that server cpus are designed for power efficiency and higher frequencies are wasteful/inefficient. But I wonder if reliability is also a factor, since there are applications for high single threaded performance, but even special high-frequency server cpus never come close to consumer-grade ones.
• londons_explore 6y ago
  Could the next computer virus be one which repeatedly adds together 1111111 and 1111111 and wears out the wires that do carries, since they were only designed for typical adding, not worst-case carrying on every operation.
  • ChuckNorris89 6y ago
    The days where viruses were designed to destroy your hardware for fun are gone. Now they're just after your personal data or money.
    • mikro2nd 6y ago
      Unless you're the military.
      • deleted 6y ago
        [deleted]
    • Traubenfuchs 6y ago
      By now, shouldn't everyone have everyone's personal data already? Hackers just want to mine bitcoins.
      • blaser-waffle 6y ago
        Even with a million hacked laptops, the hash rate for BTC would be crazy. They're going for whatever is the new hotness with the alt-coins.
  • cesarb 6y ago
    A similar concept (not focusing on specific wires, but using as much power as possible) is called a "power virus" (https://en.wikipedia.org/wiki/Power_virus https://en.wikipedia.org/wiki/Power_virus). An example is cpuburn (https://web.archive.org/web/20040717190106/http://users.ev1.net/~redelm/ https://web.archive.org/web/20040717190106/http://users.ev1....), available as a Debian package (https://packages.debian.org/jessie/cpuburn https://packages.debian.org/jessie/cpuburn).
• londons_explore 6y ago
  Some Intel Atom processors die after sending more than a few terabytes over USB over their lifetime. You can easily kill a laptop by leaving the webcam on for a few weeks, and then magically all USB stops working and there is no fix other than soldering on a new CPU. I wonder if this is the reason?
  • blaser-waffle 6y ago
    Possible, though Atom had it's share of non-aging related problems, too. Ugly race conditions, etc., though I believe the older Atoms were immune to Meltdown & Spectre vulnerabilities.
  • hwillis 6y ago
    The USB issues were related to a critical flaw in the LPC clock, according to the Intel errata. USB expected lifetime traffic for the affected processors was 50 TB while active at most 10% of the time. The errata implies lower voltage systems aren't affected. To me that says simple design flaw. Something like overdriving a transistor to get more performance out of it, without realizing what relied on it. That will cause slightly different failure conditions from electromigration. https://cdrdv2.intel.com/v1/dl/getContent/600834 https://cdrdv2.intel.com/v1/dl/getContent/600834 https://www.anandtech.com/show/11110/semi-critical-intel-atom-c2000-flaw-discovered https://www.anandtech.com/show/11110/semi-critical-intel-ato...
• ashtonkem 6y ago
  I keep getting the feeling that we’re reaching the end of the line for our current CPU technology, and that new fundamental research is needed if we wish to continue improving.
  • Retric 6y ago
    Even then physics has some real limits. If 14nm is ~1,000 atoms wide you could at most double chip density 20 times. But that’s really optimistic, physical limitations rather than design or manufacturing ones are likely well before then. Such as what’s the resistance of a wire 1 atom wide?
    • ashtonkem 6y ago
      That’s what I mean; we’re reaching the end of the road for the transistor itself. We need something else, I have no idea what, but we’re clearly running out of improvements possible on transistor based CPUs
    • hwillis 6y ago
      14 nm in actual distance is only ~50 silicon atoms (~1.4 angstroms) wide. 14 nm process finFETs have a fin width of ~8 nm and in general 14 nm process transistors have a gate length of ~20 nm. > Such as what’s the resistance of a wire 1 atom wide? Quite high; you also get a lot of leakage since electrons are basically scattering elastically all the time. You can't use copper for a wire like this, you need special low-scattering conductors.
      • Retric 6y ago
        Unless I am missing something the general transister density for 14nm is vastly worse than that. If an A9 has 2 Billion transistors on a 96 mm^2 chip. That's ~45,000 transistor in a row ~= 10 mm = 10000000 nm or 35,000,000 atoms. Or 1 transistor per ~777x777 atoms except that’s across multiple layers so hand wave ~1,000 atoms.
        • hwillis 6y ago
• bunnie 6y ago
  Anyone else catch this gem: But if you are creating a chip that other people will create software for...then you don’t really know. This is in the context of assessing usage duty cycles of circuits for aging purposes. I can imagine an era of exploits that rely on "aging out" paths that were assumed to be rarely used. Like rowhammer, but persistent -- fire up a process on a random cloud instance, run a tight loop of code to wear out an exploitable path in e.g. SGX, rinse lather repeat until you have the coverage you need...
  • est31 6y ago
    I think in the long term, we'll get away from the concept of general purpose processing units towards some units that have the right architecture and wear prevention to execute untrusted code and others which require less power but wear out more quickly. There will be domains for all those types of computing.
    • Kye 6y ago
      That already happens, but they always seem to rejoin the CPU. GPUs are headed that way. Math coprocessors went back a long time ago. https://en.wikipedia.org/wiki/Coprocessor https://en.wikipedia.org/wiki/Coprocessor
      • est31 6y ago
        You can have the CPU share the die with the secure cores, but you'd need to figure out a lot of complexity, like dealing with memory access pattern leakage due to a shared memory bus. The less things you share, the less the performant parts need to care about security, and the secure parts need to care about performance.
  • hwillis 6y ago
    Possible but unlikely IMO. For one thing it would be trivial to detect. To be a suitable attack surface it would need to wear out ~>100x faster than the most robust pathways (months instead of years). I am spectacle that manufacturing allows for that degree of flexibility. I would be more worried about two related issues: 1. If someone figures out how to focus execution that you'd normally assume distributed in a single area. The simplest example would be to write the first line of cache over and over again; that kind of thing has extensive protection but the principle is reasonable. I'm not sure what you'd use for this. 2. Aging related issues can be worked around; if a subunit loses performance you can give it more time to settle and reorder the pipeline around it. That would open up entirely new classes of timing attacks. You run a quick scan of every combination of execution paths (to find the biggest overlap of underperforming transistors) and you'll be able to make attacks using any number of extremely hard to predict timing combinations.
• abjecton 6y ago
  I bet there are some people that see this as a feature.
• ruslan 6y ago
  In an event when CPUs become spare part, computing devices should be designed to allow fast repare or even hot-swap. Similar to HDDs, one can maintain a constant supply of CPUs in store that allows to change wore out parts fast without devices being rebooted or service interrupted, anytime. This will solve all the longitivity issues while supporting sales on the expense of extra work/labour. Win-win.
  • WrtCdEvrydy 6y ago
    I wonder if we'll get to the point where the motherboard has a basic 14nm processor and the processor you buy is a co-processor on 5nm or 3nm process. Anything goes wrong, Windows keeps running on the 14nm processor and you can swap the co-processor.
    • buran77 6y ago
      I think you're better off having a spare machine and your data in the cloud than to have 2 different CPUs on the same machine. It would massively increase the price and complexity, reduce reliability, etc. It's 2 machines in one box somehow. In the end your machine will not serve its purpose with the backup CPU or you would have bought one with that as a main CPU from the start. We're going in the direction where the hardware is a commodity to replace as you see fit and the data stays somewhere safe to be used regardless of device. Phone, tablet, PC, console, etc. can consume the same data. It's not ideal because I'd like hardware to be reliable, not something I can expect to die on me when I need it most but it's pretty clear we're going that way outside of niches, with most devices being exceedingly hard or impossible to upgrade or repair.
    • ruslan 6y ago
      My way of thinking was about high load servers mostly, where your idea works well for personal computing. In both cases a whole computing system should be designed to allow easy replacement of depleted silicon. Nowadays electronics designed in such a way that maintainance either extremely difficult (for an average consummer) or not possible at all, both technically and legally.
  • marcosdumay 6y ago
• ethhics 6y ago
  I do similar reliability work for power electronics (first job after BSEE). I wouldn’t have expected lifetimes at the working stress to be a concern, but I had not fully appreciated how large the E-fields were getting in these devices (about 4x larger than a 1 kVrms isolator).