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ECC RAM should be a human right

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Re: ECC RAM should be a human right

#131

Post by Night_Thastus »

phendrenad2 wrote: post #116
Night_Thastus wrote: post #67

Earlier quoted context omitted.

I'm not very familiar with hardware architecture. Could you explain why you disagree?

ECC requires extra circuitry, and that results in more cost, also more testing cost, and also more failed chips (due to more complexity). Most people have very little need for ECC. The author didn't even know that they wanted ECC until they were unlucky enough to get a stick of RAM that failed, and failed in such a way that the OS booted, but a file silently corrupted (not that common, because if a chip fails it usua…

How much more is that cost, and how does it scale? Are we talking 5%, 10%, 30%?

Re: ECC RAM should be a human right

#132

Post by diarrhea »

wizeman wrote: post #129
diarrhea wrote: post #120

Earlier quoted context omitted.

One of the prime prerequisites of e.g. zfs actually is using ECC RAM. I’m running btrfs with integrity checks, in RAID 1 so it can automatically heal. Yet it’s non-ECC and therefore still has this gaping Achilles heel.

> One of the prime prerequisites of e.g. zfs actually is using ECC RAM. ECC RAM is not a prerequisite for using ZFS. Matt Ahrens, co-creator of ZFS and still one of the main developers, said this [1]: "There's nothing special about ZFS that requires/encourages the use of ECC RAM more so than any other filesystem. If you use UFS, EXT, NTFS, btrfs, etc without ECC RAM, you are just as much at risk as if you used ZFS wi…

True, I phrased it too strongly. Let's put it this way: zfs (or btrfs, ...) can make for a bullet-proof system through checksumming and self-healing. However, its Achilles heel is non-ECC RAM. With it, at least in theory and excluding universal disaster, data can live perpetually and remain intact indefinitely. Without ECC, zfs remains at the mercy of what the RAM might get wrong. That's what I remember learning about it a while ago.

Re: ECC RAM should be a human right

#133

Post by wizeman »

diarrhea wrote: post #132
wizeman wrote: post #129

Earlier quoted context omitted.

> One of the prime prerequisites of e.g. zfs actually is using ECC RAM. ECC RAM is not a prerequisite for using ZFS. Matt Ahrens, co-creator of ZFS and still one of the main developers, said this [1]: "There's nothing special about ZFS that requires/encourages the use of ECC RAM more so than any other filesystem. If you use UFS, EXT, NTFS, btrfs, etc without ECC RAM, you are just as much at risk as if you used ZFS wi…

True, I phrased it too strongly. Let's put it this way: zfs (or btrfs, ...) can make for a bullet-proof system through checksumming and self-healing. However, its Achilles heel is non-ECC RAM. With it, at least in theory and excluding universal disaster, data can live perpetually and remain intact indefinitely. Without ECC, zfs remains at the mercy of what the RAM might get wrong. That's what I remember learning abou…

Yes, that's true.

However, even if you're not using ECC RAM, you're much better off using ZFS or btrfs, because due to their frequent checksumming and checksum validations, these filesystems will usually detect memory corruption much sooner than if you didn't use them.

This could be immensely helpful in scenarios such as the great^4-parent poster.

Note that bad hardware is not limited to non-ECC RAM. ZFS and btrfs help just as much in detecting other kinds of bad hardware, such as bad SATA cables, bad disks, bad disk/SATA controllers, bad CPUs, bad power supply, etc.

But of course, once these checksum errors are flagged by ZFS/btrfs, it's a signal to test and fix/replace your hardware, not keep using a machine with bad hardware.

And yes, while ZFS and btrfs cannot fix errors that happen before the checksumming takes place (e.g. due to bad RAM, bad CPUs, etc), they can still detect these kinds of errors (in some cases, at least), especially when they happen after checksumming already took place. And they definitely can detect and fix errors in the rest of the data-to-storage-and-back path (e.g. bad disk cables, bad disks or disk controllers, etc).

Re: ECC RAM should be a human right

#134

Post by antifa »

karmakaze wrote: post #104
hamandcheese wrote: post #75

Earlier quoted context omitted.

AMD ryzen CPUs have ECC support, but it varies by motherboard. My home NAS runs a Ryzen in an ASrock Rack motherboard with ECC ram. I never did figure out a way to verify that the ECC is working/if it is able to report errors (to the kernel?). It was also a bit hard finding the right ram, but there’s a brand called Nemix that I found. I was a bit sketched out by the brand, but the chips themselves were Micron.

AMD used to not segment ECC for non-consuner lines. It wasn't very popular with consumers. So I can't really blame them for not supporting it well. One way that is a good balance is to make it work but not officially supported on consumer lines. Then it's up to mb vendors and buyers to take advantage if worthwhile to them. That's enough to not cut into non-consuner lines or add support costs to consumer pricing. One…

> I don't hear Apple users complain much at all about lack of ECC options.

Comes up in almost every Apple Silicon thread.

Re: ECC RAM should be a human right

#135

Post by adhoc32 »

jsz0 wrote: post #80

Personally used about an even split of ECC vs. non-ECC RAM over the last ~30 years and can't say I've ever encountered any problems with non-ECC RAM. If it happened it was no significance for me to notice. Professionally yeah I've run across a server here and there report bit errors but it was a four leaf clover the of thing. Not unheard of but not common. The more important thing in my experience is using high quali…

Silent data corruption is silent. ECC should be mandatory just for the error reporting. The system should inform the user that a DIMM has gone bad and needs replacement.

Re: ECC RAM should be a human right

#136

Post by karmakaze »

antifa wrote: post #134
karmakaze wrote: post #104

Earlier quoted context omitted.

AMD used to not segment ECC for non-consuner lines. It wasn't very popular with consumers. So I can't really blame them for not supporting it well. One way that is a good balance is to make it work but not officially supported on consumer lines. Then it's up to mb vendors and buyers to take advantage if worthwhile to them. That's enough to not cut into non-consuner lines or add support costs to consumer pricing. One…

> I don't hear Apple users complain much at all about lack of ECC options. Comes up in almost every Apple Silicon thread.

I wasn't aware. Did some searching around and it mostly concerns the Mac Pro/Studio products in discussions. I was thinking more along the lines of regular MacBook Pros and such. Using ECC in products priced much higher doesn't change things elsewhere.

Re: ECC RAM should be a human right

#137

Post by sliken »

willis936 wrote: post #76
RealityVoid wrote: post #12

Earlier quoted context omitted.

I doubt that would actually be useful with overclocking. I don't know the arch of the modern PC well enough to say with 100% confidence, but on embedded arches, the RAM has the parity bits checked when they get placed on the bus. If the error happens on data retrieval(or was already present) , then the ECC saves you, but if it happen anywhere else... not really? I don't know if.. ALU's for example automatically inclu…

The GTX 1080 has GDDR5X, which has ECC. I was able to dial in my memory OC on that card by increasing the clock then running memory throughput benchmarks until the throughput was maxed out. At the point where errors start the theroughput would decrease, but nothing would fail. Assuming stationary processes this is pretty nice. Maybe bump back 5% for margin.

I believe that's inside the chip, much like DDR5. However that doesn't help if there's an error introduced by the packages, pin, board traces, CPU pins, or CPU.

Better than nothing, but not full ECC either.

Re: ECC RAM should be a human right

#138

Post by gautamcgoel »

Retric wrote: post #128
gautamcgoel wrote: post #107

Earlier quoted context omitted.

Actually, Samsung claimed a factor of a million lower error rate in DDR5 vs DDR4 due to the on-die ECC. Source: https://www.anandtech.com/show/16900/samsung-teases-512-gb-d...

> The company details a 512 GB module of DDR5 memory, running at DDR5-7200, designed for server and enterprise use. That just shows how useful ECC memory is not that these bit flips didn’t occur.

If you scroll down a bit, the article shows a slide from Samsung claiming that DDR5 improves error rates by a factor of 10^6.

Re: ECC RAM should be a human right

#139

Post by [deleted] »

gautamcgoel wrote: post #138
Retric wrote: post #128

Earlier quoted context omitted.

> The company details a 512 GB module of DDR5 memory, running at DDR5-7200, designed for server and enterprise use. That just shows how useful ECC memory is not that these bit flips didn’t occur.

If you scroll down a bit, the article shows a slide from Samsung claiming that DDR5 improves error rates by a factor of 10^6.

[deleted]

Re: ECC RAM should be a human right

#140

Post by [deleted] »

gautamcgoel wrote: post #138
Retric wrote: post #128

Earlier quoted context omitted.

> The company details a 512 GB module of DDR5 memory, running at DDR5-7200, designed for server and enterprise use. That just shows how useful ECC memory is not that these bit flips didn’t occur.

If you scroll down a bit, the article shows a slide from Samsung claiming that DDR5 improves error rates by a factor of 10^6.

[deleted]
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