3 ms·

An article of frequency of errors http://lambda-diode.com/opinion/ecc-memory-2 http://lambda-diode.com/opinion/ecc-memory-2

jjeaff 9y ago
There are plenty of papers that put the error frequency orders of magnitude lower than. But even if true, so what? What are you doing on a workstation where a bit flipped every 3 days is going to cause a problem? Anything critical is going to have a software check. I just have never seen any legitimate argument for needing it in a workstation.
- com2kid 9y ago
  Having worked on system where we had a crc on almost all data structures, let me tell you that bit flips happen more often then you want to know. Not everyone crcs 100% of their structs. If they don't, data is being slowly corrupted.
  - jjeaff 9y ago
    How do you know they were bit flips? And if they were, how do you know they were soft errors that could have been corrected with ecc and not hard errors that would have happened either way?
    - com2kid 9y ago
      Because we had insanely good crash reporting and we root caused every crash report we got in that had more than half a dozen hits in the wild. Hardware was at fault. Turns out suppliers push the truth a bit here and there about their chips, what is supposed to be an identical part # isn't always identical, parts from different manufacturers that are supposed to be interchangeable aren't, and technical manuals aren't always the best. We had (what we thought was) rigorous memory testing in place at the factory, but under certain extreme conditions there was a 100% reproducible flip of a few bits in RAM. It was almost always the same bits, thankfully, that made it possible to track down!
- protomyth 9y ago
  > What are you doing on a workstation where a bit flipped every 3 days is going to cause a problem? Depends what bit flips. Given some of the file formats out there, the bit flip just before it is written to the disc might be fatal. > Anything critical is going to have a software check. I would love to see someone go through github and analyze if that is true. I just cannot imagine why it would be acceptable to have bit errors when a preventative measure is available. If the industry would stop looking at it as a value add, the cost would come down and we all would benefit from a more stable platform.
  - jjeaff 9y ago
    >we all would benefit from a more stable platform. What instability are you talking about? Has anyone experience any instability ever on a workstation that could have been attributed to a cosmic ray bit flip? I wouldn't trade a 10% memory performance drag for ECC if the memory was cheaper than standard.
    - protomyth 9y ago
      > What instability are you talking about? By definition, if the bits can flip in a way that wasn't intended then it is not stable. I'll take the 10% because I pretty sure getting to wrong 10% faster is not worth it to me.

jjeaff 9y ago

There are plenty of papers that put the error frequency orders of magnitude lower than. But even if true, so what? What are you doing on a workstation where a bit flipped every 3 days is going to cause a problem? Anything critical is going to have a software check. I just have never seen any legitimate argument for needing it in a workstation.

com2kid 9y ago
Having worked on system where we had a crc on almost all data structures, let me tell you that bit flips happen more often then you want to know. Not everyone crcs 100% of their structs. If they don't, data is being slowly corrupted.
- jjeaff 9y ago
  How do you know they were bit flips? And if they were, how do you know they were soft errors that could have been corrected with ecc and not hard errors that would have happened either way?
  - com2kid 9y ago
    Because we had insanely good crash reporting and we root caused every crash report we got in that had more than half a dozen hits in the wild. Hardware was at fault. Turns out suppliers push the truth a bit here and there about their chips, what is supposed to be an identical part # isn't always identical, parts from different manufacturers that are supposed to be interchangeable aren't, and technical manuals aren't always the best. We had (what we thought was) rigorous memory testing in place at the factory, but under certain extreme conditions there was a 100% reproducible flip of a few bits in RAM. It was almost always the same bits, thankfully, that made it possible to track down!
protomyth 9y ago
> What are you doing on a workstation where a bit flipped every 3 days is going to cause a problem? Depends what bit flips. Given some of the file formats out there, the bit flip just before it is written to the disc might be fatal. > Anything critical is going to have a software check. I would love to see someone go through github and analyze if that is true. I just cannot imagine why it would be acceptable to have bit errors when a preventative measure is available. If the industry would stop looking at it as a value add, the cost would come down and we all would benefit from a more stable platform.
- jjeaff 9y ago
  >we all would benefit from a more stable platform. What instability are you talking about? Has anyone experience any instability ever on a workstation that could have been attributed to a cosmic ray bit flip? I wouldn't trade a 10% memory performance drag for ECC if the memory was cheaper than standard.
  - protomyth 9y ago
    > What instability are you talking about? By definition, if the bits can flip in a way that wasn't intended then it is not stable. I'll take the 10% because I pretty sure getting to wrong 10% faster is not worth it to me.