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There are several plausible levels of "support" where ECC is concerned: 0. Not supported at all (i.e., if you plug ECC RAM, your system won't boot). 1. ECC RA

by boris 3y ago

There are several plausible levels of "support" where ECC is concerned: 0. Not supported at all (i.e., if you plug ECC RAM, your system won't boot). 1. ECC RAM can be plugged but the ECC functionality is not used (i.e., there is no relevant traces/circuitry/etc). 2. ECC functionality is present (i.e., the circuitry is there) but it was not validated by the motherboard manufacturer to be functioning correctly (i.e., detecting/correcting errors). 3. ECC functionality is present and was validated by the motherboard manufacturer. This is the level one would expect from the server-grade boards from a reputable manufacturer like Supermicro. In case of the AMD processors, when you see "ECC supported", it's anyone's guess which level it is. This is in contrast with Intel, where if it says CPU/chipset supports ECC, then you know it really does. I bet Intel won't allow a motherboards manufacturer to sell a board with chipset like W680 without validated ECC support.

theevilsharpie 3y ago
Ryzen consumer CPUs use the same memory controller as their EPYC counterparts, and have full ECC support if the rest of the platform (i.e., motherboard, DIMMs) also supports ECC. What separates Ryzen from its professional-grade counterparts is that ECC support is an optional part of the consumer Ryzen platform spec, which means that it's up to the motherboard vendor to enable support for it. Some motherboards don't have any support at all, some have ECC support as an explicitly-advertised feature, and many have ECC support but it's not explicitly advertised (simply listed as a footnote in the manual). That's different from the way Intel does it, where Intel has explicit control over what the platform's feature are, and uses that control to aggressively segment their markets. Intel's approach makes easier to reason about ECC support as a buyer, but you pay for it with the lack of flexibility compared to AMD's platform (and you literally pay more for ECC).
- LtdJorge 3y ago
  Yes, this is the correct explanation. Intel basically forbids ECC on consumer HW.
  - ClumsyPilot 3y ago
    They use safety and correctness for market segmentation. Kinda evil
    - sitkack 3y ago
      Not kinda, def evil.
- boris 3y ago
  > lack of flexibility compared to AMD's platform You mean flexibility to claim ECC support but not doing any validation to make sure it actually works? Does any AMD motherboard manufacturer actualy states that "ECC is supported and has been validated"? I think the muddy waters that AMD has created would warrant such an explicit statement.
  - theevilsharpie 3y ago
    > You mean flexibility to claim ECC support but not doing any validation to make sure it actually works? The actual ECC functionality is part of the memory controller, which is entirely AMD's domain. The ECC functionality of the memory controller is fully validated. Whether or not ECC support is present on the rest of the platform is the responsibility of the system builder. However, if the platform isn't fully ECC-capable (e.g., you're using non-ECC DIMMs, the motherboard doesn't have the necessary electrical traces, ECC support is disabled in the UEFI, etc.), this will result in the memory controller disabling ECC support, which is visible to the operating system and is something that you -- the end user -- can verify. > Does any AMD motherboard manufacturer actualy states that "ECC is supported and has been validated"? Yes. ECC support will be listed in the motherboard's spec sheet and manual. There also motherboards marketed for professional use where ECC support is explicitly advertised in the vendor's marketing. > I think the muddy waters that AMD has created would warrant such an explicit statement. AMD's official statement regarding ECC support on Ryzen is that it's supported if the motherboard also supports it. I'm not sure how they can be any clearer without making ECC a mandatory feature of the platform.
- MayeulC 3y ago
  IIRC AMD doesn't validate the ECC functionality on their ryzen chips? So you could theoretically end up with a defective ECC circuitry if unlucky. I think that was the case for the first generations, it may also have changed or I may be misremembering.
  - adrian_b 3y ago
    That was in the past (true for Zen 1 and Zen 2 Ryzen). It is no longer true (after Intel enabled ECC in some desktop SKUs, starting with Alder Lake, AMD plussed by validating ECC in all desktop and mobile Ryzens). Now all Zen 3 and Zen 4 CPUs, both desktop and laptop, have explicit ECC support, which means that ECC must be validated by AMD in all of them. If any current AMD CPU happened to have defective ECC, that would be a completely defective CPU, which must be replaced by the vendor. Despite the fact that all laptop Ryzen 6000 and Ryzen 7000 CPUs support ECC, I have not seen yet any AMD laptop or SFF computer with ECC support. On the other hand it is much easier to find AM5 MBs with ECC support than Intel W680 MBs.
    - mananaysiempre 3y ago
      The AMD website says the non-PRO 7x40 laptop Ryzens have no ECC support[1], and the Framework folks have said that AMD told them there’s no ECC on non-PRO 7x40 laptop Ryzens[2]. If plugged in, ECC modules will work, but without the error-correction functions. (Edited to reflect the current state of the website, as it used to say ECC support was present[3].) [1] e.g. https://www.amd.com/en/product/13186 https://www.amd.com/en/product/13186 [2] https://community.frame.work/t/responded-amd-batch-1-guild/28693/196 https://community.frame.work/t/responded-amd-batch-1-guild/2... [3] https://web.archive.org/web/20230513075641/https://www.amd.com/en/product/13186 https://web.archive.org/web/20230513075641/https://www.amd.c... (here “FP7r2” is the version for use with interchangeable DDR5 modules rather than with soldered LPDDR5)
      - adrian_b 3y ago
        This is very weird. I have saved the page from your link on the 17th of July. In the saved page it is written: "ECC Support: Yes (FP7r2 only; Requires platform support)" The same was written at all AMD Rembrandt and Phoenix models, and it has been written in all such mobile CPU specifications at least since the beginning of 2022, so at least during a year and a half, if not more. The ECC support was available only with DDR5 SODIMM memory, not with LPDDR5 memory, and only in the FP7r2 package, and neither in the FP7 nor in the FP8 packages. Perhaps AMD has discontinued the FP7r2 package, but this is not mentioned in the specifications. Either that, or they have decided right now that they may charge more for PRO models, or save on testing on non-PRO models. Either way, it seems a stupid move for AMD to degrade right now their mobile CPU specifications, when Intel will launch Meteor Lake, which is likely to be better than AMD Phoenix. AMD mobile Zen 5 will be better than Meteor Lake, but until its launch it remains about a half of year, supposing that it will not be delayed.
- formerly_proven 3y ago
  AMD Ryzen APUs don't support ECC unless they're the OEM-only PRO variant. (Edit: These are way more attractive for home server use because they consume a lot less power than the Ryzen CPUs when idle)
  - cassianoleal 3y ago
    I was looking for this before I posted. If anyone is looking for one of these standalone, outside of a full build, I bought a Ryzen 7 PRO 4750G about a year or 2 ago from AliExpress. It's been running a homeserver 24x7 since then and I never had any issues with it. YMMV of course.
  - adrian_b 3y ago
    All mobile Ryzen 6000 and Ryzen 7000 APUs (Zen 3 or Zen 4) support ECC, unlike in the earlier generations, where ECC was restricted to PRO variants. Unfortunately, none of the small computers that use them supports ECC on the MB. It is expected that AMD will launch a desktop Zen 4 APU in the near future. If that happens, it remains to be seen whether ECC will remain enabled in it, like in the current laptop packages, but there seems to be no reason to disable it.
    - adrian_b 3y ago
      I can no longer edit the previous message, but I must mention that, as pointed by another poster, some time during the last couple of months AMD has changed the specifications of all their mobile Ryzen CPUs. While during at least one year and a half all the laptop CPU specifications for Ryzen 6000 and Ryzen 7000 specifications have included a clear statement that ECC is supported, in the very recent past this statement has been removed from all AMD mobile CPU (non-PRO) specifications, for unknown reasons.
sidewndr46 3y ago
Given this, why would anyone buy an AMD CPU if they need ECC?

by boris 3y ago

theevilsharpie 3y ago

Ryzen consumer CPUs use the same memory controller as their EPYC counterparts, and have full ECC support if the rest of the platform (i.e., motherboard, DIMMs) also supports ECC. What separates Ryzen from its professional-grade counterparts is that ECC support is an optional part of the consumer Ryzen platform spec, which means that it's up to the motherboard vendor to enable support for it. Some motherboards don't have any support at all, some have ECC support as an explicitly-advertised feature, and many have ECC support but it's not explicitly advertised (simply listed as a footnote in the manual). That's different from the way Intel does it, where Intel has explicit control over what the platform's feature are, and uses that control to aggressively segment their markets. Intel's approach makes easier to reason about ECC support as a buyer, but you pay for it with the lack of flexibility compared to AMD's platform (and you literally pay more for ECC).

LtdJorge 3y ago
Yes, this is the correct explanation. Intel basically forbids ECC on consumer HW.
- ClumsyPilot 3y ago
  They use safety and correctness for market segmentation. Kinda evil
  - sitkack 3y ago
    Not kinda, def evil.
boris 3y ago
> lack of flexibility compared to AMD's platform You mean flexibility to claim ECC support but not doing any validation to make sure it actually works? Does any AMD motherboard manufacturer actualy states that "ECC is supported and has been validated"? I think the muddy waters that AMD has created would warrant such an explicit statement.
- theevilsharpie 3y ago
  > You mean flexibility to claim ECC support but not doing any validation to make sure it actually works? The actual ECC functionality is part of the memory controller, which is entirely AMD's domain. The ECC functionality of the memory controller is fully validated. Whether or not ECC support is present on the rest of the platform is the responsibility of the system builder. However, if the platform isn't fully ECC-capable (e.g., you're using non-ECC DIMMs, the motherboard doesn't have the necessary electrical traces, ECC support is disabled in the UEFI, etc.), this will result in the memory controller disabling ECC support, which is visible to the operating system and is something that you -- the end user -- can verify. > Does any AMD motherboard manufacturer actualy states that "ECC is supported and has been validated"? Yes. ECC support will be listed in the motherboard's spec sheet and manual. There also motherboards marketed for professional use where ECC support is explicitly advertised in the vendor's marketing. > I think the muddy waters that AMD has created would warrant such an explicit statement. AMD's official statement regarding ECC support on Ryzen is that it's supported if the motherboard also supports it. I'm not sure how they can be any clearer without making ECC a mandatory feature of the platform.
MayeulC 3y ago
IIRC AMD doesn't validate the ECC functionality on their ryzen chips? So you could theoretically end up with a defective ECC circuitry if unlucky. I think that was the case for the first generations, it may also have changed or I may be misremembering.
- adrian_b 3y ago
  That was in the past (true for Zen 1 and Zen 2 Ryzen). It is no longer true (after Intel enabled ECC in some desktop SKUs, starting with Alder Lake, AMD plussed by validating ECC in all desktop and mobile Ryzens). Now all Zen 3 and Zen 4 CPUs, both desktop and laptop, have explicit ECC support, which means that ECC must be validated by AMD in all of them. If any current AMD CPU happened to have defective ECC, that would be a completely defective CPU, which must be replaced by the vendor. Despite the fact that all laptop Ryzen 6000 and Ryzen 7000 CPUs support ECC, I have not seen yet any AMD laptop or SFF computer with ECC support. On the other hand it is much easier to find AM5 MBs with ECC support than Intel W680 MBs.
  - mananaysiempre 3y ago
    The AMD website says the non-PRO 7x40 laptop Ryzens have no ECC support[1], and the Framework folks have said that AMD told them there’s no ECC on non-PRO 7x40 laptop Ryzens[2]. If plugged in, ECC modules will work, but without the error-correction functions. (Edited to reflect the current state of the website, as it used to say ECC support was present[3].) [1] e.g. https://www.amd.com/en/product/13186 https://www.amd.com/en/product/13186 [2] https://community.frame.work/t/responded-amd-batch-1-guild/28693/196 https://community.frame.work/t/responded-amd-batch-1-guild/2... [3] https://web.archive.org/web/20230513075641/https://www.amd.com/en/product/13186 https://web.archive.org/web/20230513075641/https://www.amd.c... (here “FP7r2” is the version for use with interchangeable DDR5 modules rather than with soldered LPDDR5)
    - adrian_b 3y ago
      This is very weird. I have saved the page from your link on the 17th of July. In the saved page it is written: "ECC Support: Yes (FP7r2 only; Requires platform support)" The same was written at all AMD Rembrandt and Phoenix models, and it has been written in all such mobile CPU specifications at least since the beginning of 2022, so at least during a year and a half, if not more. The ECC support was available only with DDR5 SODIMM memory, not with LPDDR5 memory, and only in the FP7r2 package, and neither in the FP7 nor in the FP8 packages. Perhaps AMD has discontinued the FP7r2 package, but this is not mentioned in the specifications. Either that, or they have decided right now that they may charge more for PRO models, or save on testing on non-PRO models. Either way, it seems a stupid move for AMD to degrade right now their mobile CPU specifications, when Intel will launch Meteor Lake, which is likely to be better than AMD Phoenix. AMD mobile Zen 5 will be better than Meteor Lake, but until its launch it remains about a half of year, supposing that it will not be delayed.
formerly_proven 3y ago
AMD Ryzen APUs don't support ECC unless they're the OEM-only PRO variant. (Edit: These are way more attractive for home server use because they consume a lot less power than the Ryzen CPUs when idle)
- cassianoleal 3y ago
  I was looking for this before I posted. If anyone is looking for one of these standalone, outside of a full build, I bought a Ryzen 7 PRO 4750G about a year or 2 ago from AliExpress. It's been running a homeserver 24x7 since then and I never had any issues with it. YMMV of course.
- adrian_b 3y ago
  All mobile Ryzen 6000 and Ryzen 7000 APUs (Zen 3 or Zen 4) support ECC, unlike in the earlier generations, where ECC was restricted to PRO variants. Unfortunately, none of the small computers that use them supports ECC on the MB. It is expected that AMD will launch a desktop Zen 4 APU in the near future. If that happens, it remains to be seen whether ECC will remain enabled in it, like in the current laptop packages, but there seems to be no reason to disable it.
  - adrian_b 3y ago
    I can no longer edit the previous message, but I must mention that, as pointed by another poster, some time during the last couple of months AMD has changed the specifications of all their mobile Ryzen CPUs. While during at least one year and a half all the laptop CPU specifications for Ryzen 6000 and Ryzen 7000 specifications have included a clear statement that ECC is supported, in the very recent past this statement has been removed from all AMD mobile CPU (non-PRO) specifications, for unknown reasons.

sidewndr46 3y ago

Given this, why would anyone buy an AMD CPU if they need ECC?