ECC is essentially mandatory for ZFS. Assuming that is you prefer your data uncorrupted.
ECC and DDR5
91–100 of 162 posts
Re: ECC and DDR5
#92Earlier quoted context omitted.
There is a lot of direct evidence from increased error rates in computers on airplanes.
That's a much weaker statement than "the primary source of uncorrelated bit flips is cosmic radiation".
The word "uncorrelated" is doing a lot of heavy lifting in that claim. Most DRAM error sources are pretty clearly correlated, if you're paying any attention.
Re: ECC and DDR5
#93I've always thought it odd that we don't use ECC as a standard on all computers. I think people really downplay the impact of memory issues. They can be devastating, especially over time. They will slowly corrupt your file system, documents, binary files, code, everything. You notice when things like your compressed files start giving CRC/checksum errors or your downloads don't match SHA-512. You are then left with t…
> You notice when things like your compressed files start giving CRC/checksum errors or your downloads don't match SHA-512.
And 9 times out of 10 (probably much more) it will be faulty storage, not RAM.
I'd say you are way overestimating impact of no-ECC.
Re: ECC and DDR5
#94I've always thought it odd that we don't use ECC as a standard on all computers. I think people really downplay the impact of memory issues. They can be devastating, especially over time. They will slowly corrupt your file system, documents, binary files, code, everything. You notice when things like your compressed files start giving CRC/checksum errors or your downloads don't match SHA-512. You are then left with t…
> You notice when things like your compressed files start giving CRC/checksum errors or your downloads don't match SHA-512. And 9 times out of 10 (probably much more) it will be faulty storage, not RAM. I'd say you are way overestimating impact of no-ECC.
You need the ECC RAM for your filesystem with integrity only then can you be confident you aren't going to be familiar with a concept like this happening 9 or 10 times.
Re: ECC and DDR5
#95I've always thought it odd that we don't use ECC as a standard on all computers. I think people really downplay the impact of memory issues. They can be devastating, especially over time. They will slowly corrupt your file system, documents, binary files, code, everything. You notice when things like your compressed files start giving CRC/checksum errors or your downloads don't match SHA-512. You are then left with t…
> You notice when things like your compressed files start giving CRC/checksum errors or your downloads don't match SHA-512. And 9 times out of 10 (probably much more) it will be faulty storage, not RAM. I'd say you are way overestimating impact of no-ECC.
...No? Faulty storage will almost always show up as I/O errors, modern storage generally doesn't want to send a block of data to the CPU if there is an error in it. If your bits are flipping, chances are it's RAM and not storage. Your storage already has ECC.
Some crappy flash drives might not do this, though. Seems to behave like a floppy disk at times.
Re: ECC and DDR5
#96Earlier quoted context omitted.
When I last looked at this (a couple of years ago), it wasn't just the cost difference—the ECC memory available to purchase was also slower than non-ECC offerings, or at least cost significantly more if I actually wanted the same speed. At least for me, going ECC simply didn't make sense. Caveat that I was building a gaming PC at that time, I might have gone differently for a home server. And, this was before the mem…
There are absolutely fast DDR5 ECC DIMMs[1]. Just break out your wallet (and piggy bank, and rainy day fund, and..) The main reason there aren’t more options here is that a) high-frequency memory usually isn’t sufficiently stable, unless binned, and b) there’s very, very, very little demand. [1] https://v-color.net/products/ddr5-ocrdimm-amd-wrx90-workstat...
Right, my point was that it's no longer 3% of the system cost.
Re: ECC and DDR5
#97Earlier quoted context omitted.
> You notice when things like your compressed files start giving CRC/checksum errors or your downloads don't match SHA-512. And 9 times out of 10 (probably much more) it will be faulty storage, not RAM. I'd say you are way overestimating impact of no-ECC.
You need the ECC RAM for your filesystem with integrity only then can you be confident you aren't going to be familiar with a concept like this happening 9 or 10 times.
You can read online how often correctable errors happen to people with ECC and reporting.
Single digit - sometimes none - errors per year in systems with consumer amount of RAM.
Re: ECC and DDR5
#98The problem I have with ECC discussions is that it’s always anecdotal. There is one Google study finding memory flips with some probability in their datacenters, but it was awhile ago. Everyone repeats the statement DDR5 on-die ECC isn’t a replacement for regular ECC, but nobody ever shows data on DDR5 bitflips. That’s not a knock on this article per se, but it’d be nice to have actual data here.
i have years and terabytes of ECC DDR4 and DDR5 memories, UDIMM and RDIMM, with edac enabled all this time, and i have literally never once observed a single error correction. however, (1) i built all these computers myself (2) the servers are located on the middle floor a thick, concrete multi-story warehouse-to-office conversion. as others have said, on a correctly built computer, the source of bit flips is cosmic…
It's not just cosmic radiation or improperly built computers that result in bit flips. Row hammer is a thing :)
Re: ECC and DDR5
#99I've always thought it odd that we don't use ECC as a standard on all computers. I think people really downplay the impact of memory issues. They can be devastating, especially over time. They will slowly corrupt your file system, documents, binary files, code, everything. You notice when things like your compressed files start giving CRC/checksum errors or your downloads don't match SHA-512. You are then left with t…
This is/was classic market segmentation. Want ECC? Pay up for Xeon (server/workstation CPU)
AMD has historically supported ECC on all it's chips. That's changed in the last gen or two where some of the lower end APUs don't support ECC but the Pro APUs do and all the ryzen stuff (5, 7, 9) support ECC if you get a motherboard that supports it.
Re: ECC and DDR5
#100ECC is essentially mandatory for ZFS. Assuming that is you prefer your data uncorrupted.
It's preferred but not having it still works if you're willing to leave some potential avenues for errors to get in. However, it's not like not having ECC is a recipe for a corrupted FS.