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Non-ECC memory corrupted my hard drive image [video]

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Re: Non-ECC memory corrupted my hard drive image [video]

#41

Post by sobriquet9 »

H8crilA wrote: post #24
dale_glass wrote: post #23

Earlier quoted context omitted.

ECC isn't a terribly complicated technology, and can be used in all those cases. In limited cases, a checksum is good enough. If you checksum outgoing data, and verify it on reception, then it being corrupted in transit whether on the network card or the cable can be detected and transparently compensated for. Really, we can do much better than to "get used to it".

You are under the impression that CPUs and other chips always perform the same instructions as are written in the code, and only RAM can flip bits because DRAM is DRAM :) It can (and should! whenever possible) be improved, not fixed. There's always that pesky gamma that can hit a specific transistor, even if it is deep underground. Gamma cannot be fully stopped. At certain scales data corruption becomes directly meas…

The probability of a bit flip depends on the size of the transistor used. RAM tends to pack many small transistors.

Re: Non-ECC memory corrupted my hard drive image [video]

#42

Post by vladvasiliu »

OJFord wrote: post #36
vladvasiliu wrote: post #32

Earlier quoted context omitted.

I'm happy with my AMD based laptop. But I haven't seen any that support ECC. But I did see a Lenovo model, IIRC, that had some kind of Xeon and ECC. Not sure what the noise and battery life situations on that thing were, though.

I realise that's blurrier when it comes to laptops, but AIUI it's more a case of whether the motherboard than supports it than about the AMD chip. i.e. given a desktop CPU, as far as I know you can put it in a motherboard that either does or does not support ECC RAM.

That's right, but seeing how laptops seem to do the bare-minimum, I would be really surprised to learn than a random model, which doesn't advertise it, actually supports it.

Re: Non-ECC memory corrupted my hard drive image [video]

#43

Post by [deleted] »

justsomehnguy wrote: post #8
TacticalCoder wrote: post #2

> Why ECC Memory Is So Important Except that it's not for many use cases. It's great for servers but for people on their personal and/or work computer, it's simply not that useful. Seriously: which percentage of developers have ECC on their development machine(s)? As developers we live in a world of SSH, cryptographic hashes, checksums everywhere, Git repositories (that is a big one), Merkle trees, digital signatures…

And condoms are only 99.8% effective, so let's not use it? You can always pull out in time or verify checksu^W^W Plan B? > But really most of all I live in a world of Git repositories That's great for you , but 99% don't even know what Git is, just like checksums, cryptographic hashes, Merkle trees, digital signatures and reproducible builds . You just miss the one imortant thing: ECC isn't that helpful where you hav…

[deleted]

Re: Non-ECC memory corrupted my hard drive image [video]

#44

Post by ilyt »

H8crilA wrote: post #24
dale_glass wrote: post #23

Earlier quoted context omitted.

ECC isn't a terribly complicated technology, and can be used in all those cases. In limited cases, a checksum is good enough. If you checksum outgoing data, and verify it on reception, then it being corrupted in transit whether on the network card or the cable can be detected and transparently compensated for. Really, we can do much better than to "get used to it".

You are under the impression that CPUs and other chips always perform the same instructions as are written in the code, and only RAM can flip bits because DRAM is DRAM :) It can (and should! whenever possible) be improved, not fixed. There's always that pesky gamma that can hit a specific transistor, even if it is deep underground. Gamma cannot be fully stopped. At certain scales data corruption becomes directly meas…

Sure but once your registers, cache, data bus and address bus has ECC you have vastly smaller area that can flip.

You can even just buy (well, chipaggedon aside) ARM cores that have 2 chips running in parallel and faulting when the result is different

Re: Non-ECC memory corrupted my hard drive image [video]

#45

Post by Brian_K_White »

gruez wrote: post #29
moloch-hai wrote: post #9

We don't have ECC mainly because Intel has long been hostile to "consumer" access to ECC. Apparently this was conceived as a market segmentation scheme: people outfitting servers could get ECC when they pay a huge premium. They would thereby not be tempted to cheap out and buy consumer-grade equipment, otherwise wholly adequate to meet all their needs at a radically cheaper price. That we cannot get laptops or even d…

> That we cannot get laptops or even desk machines with ECC, and so have them crash frequently, is seen as a trivial side effect of the strategy I’m not sure what you mean by “frequently”, but my non-ECC machines definitely do not crash “frequently”. > before MS, a program crashing was grounds for a refund Source?

The problem with untrusworthy memory (or any other component) is not that your system crashes, it's that it doesn't.

Re: Non-ECC memory corrupted my hard drive image [video]

#46

Post by ilyt »

vladvasiliu wrote: post #34
dale_glass wrote: post #10

Yup, been there. Way back I had a Pentium 133 doing firewall duty in a closet. It did approximately nothing besides iptables, but of course any machine has logs, updates and so on going on. After running fine for months one day it suddenly died. I rebooted it. A few days later it died again. Another reboot. Then it died for the last time and failed to boot at all. Examination showed the disk was corrupt and couldn't…

> Since then I'm very paranoid, always run memtest on any new RAM I buy overnight, and have ECC where it's possible to have it. Yeah, I do the same, but I've learned that you have to do it regularly. In one of my desktop machines, the RAM ran fine for like two years. Then, all of sudden, random Firefox segfaults, etc. Whipped up a memtest ISO, and sure enough, one of the sticks was bad.

Weirdly enough I had same case but memory turned out to be fine, replacing power supply fixed the issue. I ran test, saw memory is bad, replaced sticks, same problem, put the sticks back in and decided to just run it (it was gaming PC).

Few months later powersupply outright died (had ~8years at that point), replaced it with good one, no memory errors.

Re: Non-ECC memory corrupted my hard drive image [video]

#47

Post by AdrianB1 »

gruez wrote: post #29
moloch-hai wrote: post #9

We don't have ECC mainly because Intel has long been hostile to "consumer" access to ECC. Apparently this was conceived as a market segmentation scheme: people outfitting servers could get ECC when they pay a huge premium. They would thereby not be tempted to cheap out and buy consumer-grade equipment, otherwise wholly adequate to meet all their needs at a radically cheaper price. That we cannot get laptops or even d…

> That we cannot get laptops or even desk machines with ECC, and so have them crash frequently, is seen as a trivial side effect of the strategy I’m not sure what you mean by “frequently”, but my non-ECC machines definitely do not crash “frequently”. > before MS, a program crashing was grounds for a refund Source?

"frequently" is very subjective or relative in this context. 25 years ago I had a crash per hour on almost any regular computer, but zero crashes per month on servers with ECC. In the past couple of years I think I had a few cases of frozen apps, but I don't remember of any OS level problem. At the same time, on servers I see from time to time ECC fixing a bit, but on the desktop or laptop I have no idea how many times corrupted bits went undetected and what is the consequence.

Re: Non-ECC memory corrupted my hard drive image [video]

#48

Post by ilyt »

rwmj wrote: post #4
TacticalCoder wrote: post #2

> Why ECC Memory Is So Important Except that it's not for many use cases. It's great for servers but for people on their personal and/or work computer, it's simply not that useful. Seriously: which percentage of developers have ECC on their development machine(s)? As developers we live in a world of SSH, cryptographic hashes, checksums everywhere, Git repositories (that is a big one), Merkle trees, digital signatures…

But if I open up an editor and write a document then that could be corrupted in RAM and then the corrupted data saved to disk. The document is likely to be more important than some ripped CDs or a git repo that I can download again. The CPU, RAM and mobo manufacturers need to get together and make ECC RAM mandatory. It's absurd that we have machines with gigabytes of storage using microscopic (nanoscopic??) capacitor…

>But if I open up an editor and write a document then that could be corrupted in RAM and then the corrupted data saved to disk. The document is likely to be more important than some ripped CDs or a git repo that I can download again.

Devils advocate: if it is just some bits in character flipped it's entirely recoverable while flipping some bits in compressed stream for video would corrupt more.

Re: Non-ECC memory corrupted my hard drive image [video]

#49

Post by AdrianB1 »

eternityforest wrote: post #40
OJFord wrote: post #36

Earlier quoted context omitted.

I realise that's blurrier when it comes to laptops, but AIUI it's more a case of whether the motherboard than supports it than about the AMD chip. i.e. given a desktop CPU, as far as I know you can put it in a motherboard that either does or does not support ECC RAM.

I'm surprised nobody has made RAM with the ECC logic built into the ram itself, that just looks like normal ram to the CPU.

It is called DDR5 - it has ECC built in the module itself. Making such a module does not make much sense if you cannot report the rate of errors, so if it is just hiding you have a bad RAM stick there is only so much value in having ECC.

Re: Non-ECC memory corrupted my hard drive image [video]

#50

Post by navjack27 »

AdrianB1 wrote: post #47
gruez wrote: post #29

Earlier quoted context omitted.

> That we cannot get laptops or even desk machines with ECC, and so have them crash frequently, is seen as a trivial side effect of the strategy I’m not sure what you mean by “frequently”, but my non-ECC machines definitely do not crash “frequently”. > before MS, a program crashing was grounds for a refund Source?

"frequently" is very subjective or relative in this context. 25 years ago I had a crash per hour on almost any regular computer, but zero crashes per month on servers with ECC. In the past couple of years I think I had a few cases of frozen apps, but I don't remember of any OS level problem. At the same time, on servers I see from time to time ECC fixing a bit, but on the desktop or laptop I have no idea how many tim…

I think sometime else is wrong if you've had a "crash" per hour.
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