7 ms·
I *detest* the crazy industry politics that made ECC memory so “special”
- spicyusername 4y agoAs opposed to having it be the default?
- db48x 4y agoYes. It should have been the default all along, but Intel has been using a strategy of market segmentation for many decades. This has made ECC rare in home computers (even in servers it isn’t ubiquitous), and more expensive than it needs to be. You have to pay extra for the CPU that supports it (even if the Xeon chip you buy is otherwise identical to the i7 you could have bought). The motherboard costs extra too, naturally. The memory itself has to have a ninth memory chip on it so you expect it to cost a little more, but usually it costs a lot more and isn’t made to the same specs. You end up with the sad choice of overclocked ram or safe ram in your gaming machine, and most people go with fast.
- Scene_Cast2 4y agoDoesn't have to be default, just nice to have it as an option. Currently, it is difficult to buy a NAS (where bit flips are arguably more important to avoid) with ECC memory, unless custom-building and carefully selecting parts.
- deleted 4y ago[deleted]
- throwawaaarrgh 4y ago"Why pay more for something good when you can pay less for something not as good?" - every consumer
- marcosdumay 4y agoHow much more for how much better? Anyway, try to take the technical specification of any consumer oriented motherboard and discover if it allows ECC.
- AreYouSirius 4y ago
- enragedcacti 4y agoI believe this is more about Intel who for probably a decade have sold consumer CPUs with memory controllers capable of using ECC memory but either disabling the feature in the chip, or more recently with Alder Lake, locking the feature behind an enterprise motherboard chipset despite the chipset not being relevant to ECC support. Having to pay a 20% premium on RAM for the stability of ECC is one thing, having to pay double, triple, or quadruple the system price to disable arbitrary locks is another.
- pedrocr 4y agoWith AMD that limitation is somewhat lifted with normal consumer CPUs and quite a few motherboards having support. Unfortunately the RAM itself has very poor availability. Very few manufacturers offer it and it tends to stick to the standard speeds without any of the overclocked-from-factory parts available with ECC. That last bit is strange because ECC is reportedly very good as a validation tool for overclocking builds so it seems like the RGB-lighted market could end up valuing it as a high-end feature too. One of the RAM manufacturers should rebrand ECC to "Extreme Clocking Capacity" and start selling it as a feature to differentiate their RAM from the competition.
- someweirdperson 4y agoIf non-ecc RAM is good enough for most fault sto only cause noticable problems rarely, its possible to sell slightly less perfect modules than with ecc, where even otherwise unnoticable problems are detected and reported. The ratio of modules returned to the manufacturer is probably higher for ecc than non-ecc. Unless ecc modules are already better selected than non-ecc at the manufacturer.
- guenthert 4y ago> That last bit is strange because ECC is reportedly very good as a validation tool for overclocking builds Well, yes, but it's not the only tool. In practice you'd use some validation software suite to find a reasonable stable configuration and afterwards prey. Overclockers, who rather than spending extra money on a CPU which assuredly delivers requested performance stress their hardware beyond specifications, are least likely to pay for the extra bits.
- acdha 4y agoHow many seconds do you need to think about this to come up with counter examples? There are entire businesses based on selling things which are better or helping buyers find them, suggesting that the rush of perceived superiority isn’t warranted. Some people can’t afford to buy anything but the cheapest but in most cases it comes down to not thinking that they use it enough to matter (e.g. the common homeowner advice to buy a cheap tool the first time & replace it better if you break it), not having a good way to tell whether something is actually better, or the market being such that there is a huge gap between the product bands. ECC falls into the latter two categories: the average buyer isn’t familiar with the issue and probably thinks the outcome would be a crash rather than silent data corruption, and Intel’s market segmentation means that you don’t have a choice in the consumer space and have to move into far more expensive and limited categories. It’s not reasonable to say price-sensitive consumers are the problem when that’s also saying “stop buying laptops”.
- someweirdperson 4y ago> when that’s also saying “stop buying laptops”. My 4 years old laptop has ecc. To see if anything has changed I just checked the recent models. The manufacturers website didn't provide any possibility to filter for ecc or mobile Xeon, but an explcit text search returned some results. Ecc still exist in laptops, its just a bit difficult to find. On the plus side, 19:10 screens are back.
- TomVDB 4y agoWhy pay for something I don’t need when there’s the option to not pay for it? - me Just yesterday, I bought an extra 64GB for my home Linux PC. I absolutely couldn’t care less about it crashing or calculating the wrong result every blue moon (in practice: never), but I did choose the RAM sticks that were $10 cheaper.
- AdrianB1 4y agoThe problem is the lack of choice, not your choice. If you were willing to pay $10 more for ECC DRAM, there would be no way to use it.
- GekkePrutser 4y agoThat's totally fine. The problem is people that do need it not having the option to pay the extra without getting a totally different "workstation-class" computer.
- IYasha 4y agoPlz tell me your IP, I'll block torrents from you :D
- sigstoat 4y agotorrents have checksums on the blocks, which your client already checks, because the internet doesn't guarantee packets arrive without corruption. it doesn't matter where the corruption comes from.
- IYasha 4y agoYes, I know. It was a joke :)
- TomVDB 4y agoI’d go dither than that and claim that almost everything of importance has checksums: Google Docs, Google Sheets, Git submissions, all my important web accounts, the traffic with my bank website and so forth. When I look at my daily home computer usage, it’s remarkable how little I calculate on my local computer that’s actually with protecting.
- vbezhenar 4y agoWhy buy mac pro for $5000 when you can buy trash can for $5. Even if it's not as good, it's much cheaper and does not look much different anyway.
- duxup 4y agoWhile I think that is true, do we have much choice in this case? The computing world is full of more and less featured products.
- fmajid 4y agoMore like "Hey, nice mission-critical database you have, deep-pocketed enterprise customer. It would be a shame if a bit-flip happened to it".
- drewg123 4y ago"Why are all products so unreliable now!?!?" -- Also every consumer, when their appliance breaks one day out of the 2 year warranty
- dwild 4y agoHow many people complains about memory corruption? This is a ridiculously rare issue, which impact is minimal, if not null, for so many people. There's an actual cost to provide ECC memory though, there's actually more hardware necessary to cover it. Obviously if more would need it, it may lower the cost because of the scale, but it will still be more. For some it's important, and for sure they will pay for it, so let them pay for it... It's not like it wasn't available, Linus just forgot to put a reminder to buy some once available (backordering them would have been even more prudent).
- sliken 4y agoRidiculously rare? That's why CDs, DVDs, blurays, caches, SSDs, spinning rust, etc all have ECC, right? Even ancient file transfer protocols like xmodem and zmodem has error correction. Bitflips aren't uncommon, it's just compression makes them much more noticeable. Without compression users might just see an occasional application crash, and just relaunch the proces.s Seems common for people collecting photos, music, etc for years go back and find some corrupted. It's hard to say exactly what happened, but with compression a bit flip it turned into a seriously corrupted file. Keep in mind that, radiation caused bit flips are rare, some failure in the chip, pin, dimm, dimm connector, motherboard, CPU pin, CPU are much more common. It's MUCH nicer to see "error on dim X, row Y, column Z" then a randomly crashing machine. Even Linus sounds like he spent hours tracking it down, and thought he was hitting a kernel bug. Isn't it worth 1/9th more memory chips to make the system robust in the face of wide variety of errors that can corrupt memory, which can lead to corrupted storage?
- deleted 4y ago[deleted]
- fabianhjr 4y agoI had a similar issue at the beginning of the year; some g. skill ddr4-3200 (with xmp) started bit-flipping on me and causing crashes. Sure enough on memtest64 those issues were clearly diagnosed. Haven't changed to ECC hardware, disabling xmp to ddr4-2333 helped with stability.
- Nursie 4y agoI replaced the RAM in my storage machine because of this earlier this year too. ZFS was reporting all sorts of errors, yet drive tests were showing no issues. I bought about 3 new drives before I realised what the root cause was. A real PITA. Next time I do a hardware refresh, ECC is definitely on the menu.
- orangepurple 4y agoI'm waiting for Linus to discover the power supply industry conspiracy next lol Joking aside, power supplies are probably the next largest source of random hardware issues in PCs today
- bioemerl 4y agoI'm confused, I've built a couple of computers and I've never had issues with the power supply. The only weird issue I've had so far was with a first generation ryzen processor causing hard locks on the computer when it was left on for more than a couple of days. Also with some bad memory causing really really weird issues all across the system. Power supplies? And some of the cheap ones I've used have just done their job and not caused any problems. Do you have any examples of what's going on with this?
- sliken 4y agoI see issues all the time with external power cubes. Devices goes wonky, look up the spec, find it's DC 12v @ 2 amps or whatever and replace the power supply. About 90% of the time the device is happy again.
- Waterluvian 4y agoA 500W power supply doesn’t mean much when the important voltage rails see such a small amount of that wattage. If you get a stock grey metal 500W power supply and try to run a modern graphics card you’ll have a far worse time than some Corsair 400W PSU. I haven’t build a PC in a decade so maybe this is old news.
- alias_neo 4y agoI think a lot of people still don't know this stuff and it's quite reasonable to expect people not to know this stuff. Not everyone is an electronic engineer, and if the overall wattage doesn't give the information people need, the sales/marketing should be forced to provide the necessary details right there on the box in "plain language"; RAM speeds are still a pet-peeve of mine. That said, I've been building PC's for ~25 years and I'm yet to have a PSU fail on me. Anecdotal I know, and with some skew as I've always tended to build near or at the top end. That said, the Ryzen hard lockups were a real disappointment for me, after spending north of £3500 on my desktop in the OG Ryzen era with an R7 1800X, I was left with a machine that frequently hard-locked when compiling code on all cores and AGESA is such a mess that if it boots at all, it takes several minutes at times to make it past POST. I really hope the next gen build I make, whatever it is is more stable because I'm not planning to go back to Intel any time soon.
- AreYouSirius 4y ago
- trynewideas 4y agoI mostly just love the idea of Linux kernel development slowing down or halting because Linus got a bad stick of RAM and doesn't like working on his laptop.
- jpgvm 4y agoIt's not that he doesn't like his laptop it's just that horsepower wise it simply doesn't compare to his monster Threadripper machine when it comes to compiling kernel trees.
- ClumsyPilot 4y agoThis has nothing to do with politics, it's market segmentations and it's the job of MBA's and business leaders to do it coreectly. The current situation demonstrates that the customer has no ability to negotiate product quality. It's debatable if that's due to ignorance or the game is just so syacked against consumers
- cma 4y agoi.e. capitalism pays vendors extra to corrupt data and price discriminate for those who need protection from the protection racket
- nopenopenopeno 4y agoThe market is always downstream from politics. Karl Marx famously used the term political economy to reference both political and economic forces, because neither is coherent without the other.
- trasz 4y ago
- CrazyStat 4y agoThe term political economy far predates Marx. I've not heard of Marx famously using it, but I don't doubt he did use it since it was an established field of inquiry at the time--the predecessor to the modern field of economics.
- nopenopenopeno 4y ago“In the 21st century, Karl Marx is probably the most famous critic of political economy, with his three volume magnum opus Capital: A Critique of Political Economy as one of his most famous books.” https://wikipedia.org/wiki/Critique_of_political_economy https://wikipedia.org/wiki/Critique_of_political_economy
- 4y ago
- sschueller 4y agoSFP the similar shit is going on and HDDs/SSDs are being vendor locked now as well.
- bpye 4y agoI don't get it for SFPs either, it seems easy enough to get SFP modules coded for whatever NIC or switch you have, so it seems like it doesn't even work.
- deleted 4y ago[deleted]
- themitigating 4y agoJust some points - The amount of memory that leaves the factory that has errors is a low percentage, not sure what it is but we can all agree it's low. - You can run memtest when you first install memory for several hours or so to be 99.99% sure your memory is good - There are outside influences and EXTREMEY RARE cases (cosmic radiation etc) where you may still get an error. If you had ECC it would protect you. - If you start getting errors (as in more than the one off cosmic flare) later you can test the memory again and determine it's damaged - Most memory you buy for builds has a lifetime warranty - ECC costs more and reduces performance by some amount So the only danger of not having ECC is exceedingly rare memory errors. If those rare instances mattered that much then you should get ECC but for everyone else how is it worth it? The argument in this post is that he wouldn't have had to go through this since the ECC would have covered the error. I just don't see the value of adding this safety system.
- tomxor 4y agoRead the email. None of your scenarios fit Linus's. TL;DR sometimes memory starts off good and goes bad later.
- themitigating 4y ago"- If you start getting errors (as in more than the one off cosmic flare) later you can test the memory again and determine it's damaged - Most memory you buy for builds has a lifetime warranty"
- xxs 4y agoall those points are irrelevant - when you do work with you computer, not just being frustrated your game has crashed. running a memtest overnight is hardly a good choice.
- themitigating 4y ago"So the only danger of not having ECC is exceedingly rare memory errors. If those rare instances mattered that much then you should get ECC but for everyone else how is it worth it?"
- Arcuru 4y ago> PS. And yes, my system is all set up for ECC - except I built it during the early days of COVID when there wasn't any ECC memory available at any sane prices. How much was ECC ram at that point? Linus is incredibly wealthy and was building a machine that would be used to gate Linux releases, so I'm very curious how much was not "sane" for his use case.
- zdw 4y agoWhen I last looked DDR4 ECC UDIMMs were 2x the price of non-ECC UDIMMs of the same capacity. This feels very wrong when the only difference is one additional chip that in terms of material only should increase the BOM price about 12.5% (going from 8->9 memory chips).
- plasticchris 4y agoMaybe it is a volume issue - not enough are produced to benefit from economies of scale in the same way
- IYasha 4y agoBut the chips are identical AND PCBs are compatible! I've seen many non-ECC modules with just one chip not soldered on. Unbuffered, of course.
- justsomehnguy 4y agoIt's 3-5 orders difference in the volume (and most of the time people buy high capacity modules) and ECC errors makes very obvious the need of replacing the module, while unregistered errors on non-ECC modules are just other 'something gone wrong' type and couldn't be diagnosed easily. Also, onr of the primary markets for ECC UDIMMs are server/pro-workstation, thia alone.adds at least 10%
- warmwaffles 4y ago> How much was ECC ram at that point? Linus is incredibly wealthy... I don't think Linus likes wasting money for the sake of wasting it.
- glowingly 4y agoWhat I am curious about, is some Nvidia cards like the A2000 have ECC, but only enough chips for a regular roundish number of RAM, like 6GB or 12GB. So when ECC is enabled, 6.25% of the RAM is used for the ECC bits. [0; 1, in the notes] Since desktop ECC gets around this by having physically more RAM ICs (usually 9 instead of 8, for example), what is the impediment from having a similar solution to Nvidia? I'd readily take a hit to memory capacity* and performance in exchange for ECC. Why can't the memory controller already do this? I should note, I'm mostly thinking of my NAS. I know ZFS can be run without ECC and some consumer solutions do. However, it seems ZFS should be run with ECC. I've already experienced observable bitrot with older images and video files, I'd rather not let it progress. [*] in this case, 12.5% if we follow typical desktop ECC allocations [0] https://www.nvidia.com/content/Control-Panel-Help/vLatest/en-us/mergedProjects/nvwks/To_change_the_ecc_state.htm https://www.nvidia.com/content/Control-Panel-Help/vLatest/en... [1] https://docs.nvidia.com/cuda/cuda-c-best-practices-guide/index.html#theoretical-bandwidth-calculation https://docs.nvidia.com/cuda/cuda-c-best-practices-guide/ind...
- jrk 4y agoI have always wondered exactly this. Market segmentation on what platforms/controllers support ECC: fine, whatever. But market segmentation of what is an “ECC DIMM” vs. a “regular DIMM”? It makes no sense that the commodity memory manufacturers have any leverage to enforce that segmentation. Is it just laziness on the part of the platform vendors (who do have leverage) not simply allow ECC with any DIMMs by giving over 1/k {bits, lines, pages, chips, whatever-granularity-they-reason-about} to parity?
- acdha 4y agoIt’s not the memory providers but the chipset manufacturers like Intel pushing customers to the expensive workstation/server lineups.
- sliken 4y agoOn the Intel side, yes. On the AMD side, no. However Intel guarantees ECC will work on their "workstation" chipsets. AMD doesn't guarantee ECC will work on their desktop/workstation chipsets. You have to go up to Epyc to find a guaranteed/tested ECC.
- helsinkiandrew 4y ago> I absolutely detest the crazy industry politics and bad vendors that have made ECC memory so "special Haven’t bought RAM for awhile, what’s he talking about? ECC RAM should be at least 1/8 more expensive (plus something for the handler)
- xxs 4y agoIn reality ECC is like twice the price, the CPU support is close non-existent too (Intel just has been disabling in the memory controller for ages... unless it's an i3 laptop - then it's available again) Just try and buy a reasonable non-server class machine that has ECC.
- sliken 4y agoNot sure where you are. But I just compared Crucial DDR5 32GB DDR5-4800 (PC5-38400) and the non-ECC (on CDW.com) is $186.99 for part (CT32G48C40U5) and $229.99 for part (MTC20C2085S1EC48BA1R) a 22% premium. All Alder Lake chips (the ones shipping in volume today) support ECC, check ark.intel.com to be sure. For example the popular i7 model (https://ark.intel.com/content/www/us/en/ark/products/134591/intel-core-i712700-processor-25m-cache-up-to-4-90-ghz.html https://ark.intel.com/content/www/us/en/ark/products/134591/...) As do all Ryzen desktop chips (5000 and 7000) do as well. Granted popular consumer products don't have ECC, but it's pretty straight forward to built it yourself. Just make sure the motherboard you buy (Intel or AMD) supports ECC.
- IYasha 4y agoAFAIR, every AMD64 CPU has ECC support. But not every motherboard had necessary layout and BIOS support. That's why I'm 20 years with AMD and choosing components carefully. Every system with > 4GB RAM should have ECC. Proven decades ago.
- xxs 4y agoThey (ryzen) sort of do - unofficially. Which also means that the motherboards won't list the memory compatibility, either... or tune the bios.
- NelsonMinar 4y agoIt's wild to me that we gave up hardware error correction on memory at the same time we increased memory sizes about 1000x, shrinking the die (and thus reliability) by a roughly similar amount.
- sliken 4y agoThis is true, but even today bit flips per GB/hour are still really low. However failures in the memory chip -> chip pin -> dimm -> dimm connector -> motherboard -> CPU socket -> CPU pin -> CPU are pretty common. Sure ECC helps with random bitflips, but it's also very useful to diagnose something is broken in the CPU <-> memory chip pipeline. It's very frustrating to debug something when the main sign of the problem is a reboot.
- natch 4y ago>And yes, my system is all set up for ECC From reading this, I guess one has to do some special setup to let a system use ECC? Been thinking about ECC myself. What would I need to do, apart from buying the DIMMs and putting them in? Some BIOS settings? Jumper settings?
- rdpintqogeogsaa 4y agoI've been through this ordeal recently, but I'm probably missing something anyway. You need to have a compatible CPU/motherboard/chipset. For normal CPUs: AMD Ryzen non-Pro APUs don't have support for it, the rest of AMD's CPUs and chipsets have unofficial support for it. You'll have to check the motherboard vendor's support page if a certain board also has support for ECC. Then you need ECC memory modules and you should stick near the qualified vendors list (QVL) here since systems are kind of pickier with ECC memory. For Intel, you're out of luck except for the W680 chipset, but motherboards seem to be scarce. For high-end desktop (HEDT) and workstations CPUs: AMD's Threadripper lineup have official ECC support, but still check with the motherboard vendor first. For Intel, most Xeons should do it, but check before you buy. The same caveat about motherboards applies here, too: Check if there's ECC support first and stick to the QVL to be safe.
- jeffbee 4y agoYou need system software to make it work right. You want to configure your system to halt as soon as possible after uncorrectable errors. You also need to prominently log correctable errors. How you achieve this is going to vary by hardware platform and operating system.
- eqvinox 4y agoHere's some prices for reference, for 32GB DDR4-3200 unregistered DIMMs in DE/AT, trying to compare otherwise equal modules: - Mushkin Essentials DIMM 32GB, DDR4-3200, CL22-22-22-52 - 85.79€ Mushkin Proline DIMM 32GB, DDR4-3200, CL22-22-22-52, ECC - 143.00€ (= 1.67×) - Kingston ValueRAM DIMM 32GB, DDR4-3200, CL22-22-22 - 117.39€ Kingston Server Premier DIMM 32GB, DDR4-3200, CL22-22-22, ECC - 147.90€ (= 1.26×) - Samsung DIMM 32GB, DDR4-3200, CL22-22-22 - 117.39€ Samsung DIMM 32GB, DDR4-3200, CL22, ECC - 152.89€ (= 1.30×) - It should be noted however that a bunch of cheap brands do not even offer ECC variants, and those may dominate the lower end of the price spectrum. So getting ECC memory may also involve choosing a more pricey brand. - References: https://geizhals.de/mushkin-essentials-dimm-32gb-mes4u320nf32g-a2344753.html?hloc=at&hloc=de https://geizhals.de/mushkin-essentials-dimm-32gb-mes4u320nf3... https://geizhals.de/mushkin-proline-dimm-32gb-mpl4e320nf32g28-a2515488.html?hloc=at&hloc=de https://geizhals.de/mushkin-proline-dimm-32gb-mpl4e320nf32g2... https://geizhals.de/kingston-valueram-dimm-32gb-kvr32n22d8-32-a2215404.html?hloc=at&hloc=de https://geizhals.de/kingston-valueram-dimm-32gb-kvr32n22d8-3... https://geizhals.de/kingston-server-premier-dimm-32gb-ksm32ed8-32hc-a2679022.html?hloc=at&hloc=de https://geizhals.de/kingston-server-premier-dimm-32gb-ksm32e... https://geizhals.de/samsung-dimm-32gb-m378a4g43ab2-cwe-a2328262.html?hloc=at&hloc=de https://geizhals.de/samsung-dimm-32gb-m378a4g43ab2-cwe-a2328... https://geizhals.de/samsung-dimm-32gb-m391a4g43bb1-cwe-a2755732.html?hloc=at&hloc=de https://geizhals.de/samsung-dimm-32gb-m391a4g43bb1-cwe-a2755...
- rasz 4y agoThis is irrelevant. Back in 286 30 pin simm times when every motherboard supported ECC price difference was ~10%. ECC was still supported on almost ever 386/486 board. Then came Intel with 430 chipsets artificially segmenting ECC exclusively for expensive server market HX offerings. https://en.wikipedia.org/wiki/Intel_430HX https://en.wikipedia.org/wiki/Intel_430HX
- eqvinox 4y agoOf course Intel segmenting ECC out of the client market is a major factor… … which does not mean other factors are "irrelevant"… … and also the price differential in ECC memory is not only a factor but also a metric as it shows that ECC memory has a "non-mainstay" surcharge created by the vast majority of users going for non-ECC. If demand were equal, the price would be 9/8 = 1.125×.
- animitronix 4y agoDidn't Torvalds have an epic rant on ECC memory at some point?
- GekkePrutser 4y agoAgreed, Intel's policy is very bad for consumers. ECC should be everywhere. It should only cost 1/8th extra.
- bpye 4y agoIt does look like some Intel 12th gen and later parts support ECC [0, 1] - but not all as I don't see it on the i3, Pentium or Celeron parts... That said you apparently require a W680 chipset motherboard [2], so that's still going to be expensive. I much prefer the situation with AMD where ECC should work on all parts, even if not all motherboard mfgs enable or validate it. [0] - https://ark.intel.com/content/www/us/en/ark/products/96149/intel-core-i512600-processor-18m-cache-up-to-4-80-ghz.html https://ark.intel.com/content/www/us/en/ark/products/96149/i... [1] - https://ark.intel.com/content/www/us/en/ark/products/134591/intel-core-i712700-processor-25m-cache-up-to-4-90-ghz.html https://ark.intel.com/content/www/us/en/ark/products/134591/... [2] - https://www.anandtech.com/show/17308/the-intel-w680-chipset-overview-ecc-for-alder-lake-workstations https://www.anandtech.com/show/17308/the-intel-w680-chipset-...
- GekkePrutser 4y agoIt's funny because the Pentium G1610T that my old Microserver G8's came with did have it. Because those Pentiums are Xeon-Pentiums somehow. But they lack hyperthreading and AES-NI making them really crap for server tasks. Intel's marketing is really in a league of their own. As soon as their branding starts making sense they will change it.
- bpye 4y agoI'm actually still running one of those old G8 Microservers, though I swapped the crappy Pentium for one of the Xeon parts. I've looked a few times and I still haven't found anything that would be a good replacement.
- muxator 4y agoSame here, my friend. Hp Microserver gen 8 upgraded with a xeon e3-1265L-v2. I am hoping for a good successor (ECC, enough bays, not too fast but cheap enough) to come out. It would be nice to have a nice little server which consumes 15-20 Watts.
- rassimmoc 4y ago
- rassimmoc 4y ago
- rocqua 4y agoSupposedly modern RAM already has built in ECC because of rowhammer etc. It's just that they don't report errors back like true ECC ram does.
- sliken 4y agoDDR5 does have "on chip ECC", but that doesn't protect as much as full ECC. Bit errors can be introduced after the bits leave the chip. It could happen on the ram chip pins, in the DIMM, the DIMM connector, the motherboard, the CPU pins, or in the CPU. So it's not just the error reporting, it's protecting against errors on the whole pipeline, not just inside the chip.
- layer8 4y agoIt doubt that, because it requires 12.5 % more bits to be stored, with corresponding increase in cost. ECC also doesn’t fully protect against Rowhammer, in particular if errors remain unreported: https://news.ycombinator.com/item?id=18508692 https://news.ycombinator.com/item?id=18508692
- lbotos 4y agoI think GP is talking about DDR5 "on-die ECC".
- Dylan16807 4y agoThe percent increase depends on how many bits you're protecting in a group. It can be a lot smaller.
- aborsy 4y agoHow frequent are bit flips in RAM, causing errors undetected by non-ECC RAM?
- mctt 4y agoGood question, so I Googled some answers: How common are RAM bit flips? Research has shown that a computer with 4GB of memory has a 96% chance of having a random “bit flip” every three days. That's a crazy high chance of data corruption occurring on your computer.18 Mar 2021 https://www.macobserver.com/columns-opinions/devils-advocate/computer-makers-negligently-ignore-bit-flip-errors/ https://www.macobserver.com/columns-opinions/devils-advocate... How often do ECC errors occur? These can all not be corrected, but are extremely rare. A 1 Gigabit ECC DRAM contains 16 Million blocks of 64 bit datawords. Per each of these 64 bit words, one error is correctable. In other words: Statistically one out of 16 million hits might be a double-bit error. https://www.intelligentmemory.com/support/faq/ecc-dram/how-often-do-ecc-correctable-single-bit-errors-occur-and-how-about-double-multi-bit-errors.php https://www.intelligentmemory.com/support/faq/ecc-dram/how-o...
- warmwaffles 4y agoI wonder how much more likely it is for random bit flips in machine shops with Thoriated tungsten rods near a CNC machine.
- adrian_b 4y agoIntel is a big company, so during its many decades of activity there have been many Intel employees who have done a lot of good things for the progress of the computing industry, but there have been also too many Intel employees who have made horrible decisions which have caused millions of Intel customers to lose a large amount of money and time, which is impossible to evaluate, because in such cases there is not enough information to disambiguate the causes of various incidents between various kinds of hardware problems and software bugs. The most damaging Intel decision was about the ECC memory, but there were also many others that are less impactful, e.g. the various ugly workarounds for the laziness of Microsoft of adding various necessary features to Windows, e.g. the System Management Mode or the Management Engine. The problem with the ECC memory has been created by Intel from 1994 to 1995, when Intel has split their top line of CPUs into two branches, Pentium (the second generation of Pentium, @ 90 or 100 MHz) and Pentium Pro. For more than a decade, since the introduction of the IBM PC, all compatible personal computers had implemented memory error detection, even if it was possible to use memory modules without error detection, if one did not care about the reliability of the computer. With Pentium and Pentium Pro, Intel has decided to introduce a market segmentation feature and they have reserved the use of ECC memory for the "professional" Pentium Pro, while removing the support for memory error detection from the Triton chipsets made for the Pentium CPUs (at that time, before AMD integrated the memory controller, the memory controller was still a part of the external northbridge chip). The successors of Pentium Pro have been rebranded as "Xeon" and they have continued for a long time to be the only Intel CPUs with support for ECC. The so called "market segmentation", even if it is practiced by a large number of companies, is just a combination of fraud with blackmail, which should have been forbidden by law in most cases. To introduce market segmentation, a company takes advantage of the fact that the majority of its customers are naive and they are not able to evaluate correctly the quality of a product that they purchase. The company then uses this fact to extract much more money from the fewer customers who actually know how to evaluate the quality. For this, the company convinces the naive customers that a lower quality is good enough for them and then the company lowers by various means the quality of the products sold at a decent price, in order to able to request an overprice from the quality-aware customers, who are forced to pay, because they do not have an alternative, since the products at the right price do not have the right quality. This scheme would not work in a competitive market, but when there are few competitors they usually follow the example of the first company which did that and they introduce the same market segmentation policy, because this will increase the profits for all. Now, because AMD did not disable ECC in Ryzens, even if AMD has provided much worse software support for this feature than Intel (in the EDAC device drivers), at least until recently, Intel has been forced eventually to enable ECC in many models of Alder Lake and Raptor Lake. Nevertheless, after many decades of lack of support in consumer CPUs, there is a lot of inertia to overcome in the availability of ECC. Even if now it is easy to find Intel desktop CPUs with ECC support, the ECC support on motherboards requires the special workstation chipsets, so the socket LGA 1700 motherboards with ECC support are hard to find and they are either expensive or with underwhelming features. All Intel CPUs for mobile applications (the U, P and H series) continue to lack ECC support. Only the HX series for laptops, which are desktop chips packaged in BGAs, have ECC support. Previously, even AMD had implemented a market segmentation by disabling ECC in their laptop CPUs. That has changed in the Ryzen 6000 Rembrandt series, which have ECC support. However the ECC support remains theoretical, because until now no laptop manufacturer has introduced any laptop with an AMD mobile CPU and with ECC memory, so there is no competition yet for the Intel mobile workstations.
- dis-sys 4y agoAll my workstations at home use ECC Reg RAM purchased online from ebay/alibaba. Most of them are from vendors selling "decommissioned" server parts. There are several good incentives to do that - such second hand server parts are cheaper than normal consumer grade parts you get extra protection & performance 256GB (32GB x 8) Samsung DDR4-2933 ECC Reg RAM for USD $550, it is pretty hard to say no to that.
- hatware 4y agoRAM errors are the last thing you'll test before your computer is fixed.
- tester756 4y agowhat's going on here? is Linus' PC something like CI/CD server for Linux development?
- someweirdperson 4y agoIs he known as Linus "Jenkins" Torvalds?
- Maursault 4y ago> it was literally a DIMM going bad in my machine randomly after 2.5 years of it being perfectly stable. Go figure. I suspect that the final phrase above is sarcastic, as well as instructive and even possibly bragging, and Linus is perfectly aware that his machine gets an exceptional amount of use compared to the average Peanuts character. RAM wears out, "And some of the degradation is noticiable if you use it intensively (as servers do)."[1] [1] https://superuser.com/questions/1568933/does-ram-degrade-over-time https://superuser.com/questions/1568933/does-ram-degrade-ove...
- temac 4y agoIIRC Intel "consummer" parts are qualified for 3 (or 5 ?) years of usage at a 30% duty cycle (and you might not find that figure publicly, but honestly you should, and intel should be mandatted to publish it). Now that is likely not exactly what RAM vendors are doing, but likely to give a rough idea of what you should expect from consummer electronics. I'm not even sure all small Xeon have better specs, but for sur you can source some models in volume for a quite low extra cost, qualified for a higher duty cycle and more years of usage.
- Maursault 4y ago> qualified for a higher duty cycle and more years of usage. Which is what? Double the 30% duty cycle? Would it be so beyond the realm of belief that Linus' box has a 80%-90% duty cycle? I'm not exactly sure where your position falls, that the RAM was defective, or that it lasted longer than expected given its increased use.
- temac 4y agoExpected by who? Those who have access to private info? As far as I'm concerned, I don't see why I should expect anything less than 100% usage if a vendor does not warn me otherwise, and countries exists where mandatory warantee is 2 years. And that's just about the law. Don't get me started on resource consumption and on my perfectly fine 10 years old computers I'll be forced to stop using soon because of litteral planned obsolecence (of MS, that's another story but a major actor of the computer industry too, and that will yield even more environmental destruction)
- fmajid 4y agoIt's not politics, but economics. Near textbook perfect price discrimination (market segmentation) by a profit-maximizing quasi-monopoly (Intel) to extract the maximum surplus out of consumers. I miss the old, less politically-correct Linus who didn't pull his punches.
- heynowheynow 4y agoLargely ignorant buyers of mass-market, commodified devices lead to intense cost wars that shed features that aren't "essential." If a buyer wants ECC in a laptop or desktop, typically they have to purchase a workstation-class machine that costs 4-5x of low-budget models. Memory issues can be caused by the PSU, motherboard, the CPU, or the memory itself. Personally, I always run memtest86 and memtest86+ for 2 days on any new components. Out-of-date but pertinent: https://cr.yp.to/hardware/ecc.html https://cr.yp.to/hardware/ecc.html (c. 1999-2006) Other risks: https://defcon.org/images/defcon-21/dc-21-presentations/Schultz/DEFCON-21-Schultz-Examining-the-Bitsquatting-Attack-Surface-WP.pdf https://defcon.org/images/defcon-21/dc-21-presentations/Schu... The mitigation of bitsquatting requires ECC in network gear also. Furthermore, ECC isn't just about the memory type but having integrity in data buses, caches, storage, and network protocols also. Home system is 96 thread, 512 GiB (16 x 32GB ECC Registered DDR4-3200), numerous SSDs and HDDs running RAID.
- timzaman 4y agoI wonder if he couldnt have used the memtest kernel parameter: memtest= [KNL,X86,ARM,M68K,PPC,RISCV] Enable memtest Format: <integer> default : 0 <disable> Specifies the number of memtest passes to be performed. Each pass selects another test pattern from a given set of patterns. Memtest fills the memory with this pattern, validates memory contents and reserves bad memory regions that are detected.
- andromaton 4y agoHistorical note: PC RAM modules (SIMMs) in the 80's and 90's commonly had 9 bits per byte. The extra bit was parity, a simple form of error detection. Eventuality, as a cost saving measure, some modules faked the parity bit.
- the_arcadian 4y agoI understand why any commentary from Torvalds is notable, but when I read this my takeaway isn't that we need ECC everywhere, its that a hardware component failed much sooner than it should have (I would have liked to have known who the manufacturer was) and that his ability to accurately diagnose the failing component was hampered by a shortage of effective diagnostic tools and perhaps his own lack of hardware troubleshooting experience. But maybe I'm missing something here.