3 ms·

Don't make the mistake of thinking Non-ECC ram doesn't have built-in error protection it's just not as robust. Random memory bit flips are pretty rare but it ta

Don't make the mistake of thinking Non-ECC ram doesn't have built-in error protection it's just not as robust. Random memory bit flips are pretty rare but it takes multiple at the same time for ECC to be effective. Additionally, the thing that makes no sense about ECC Ram is that you have no parity checks when data is in transit too and from the CPU(s). So a little corrosion on a trace or bad capacitor and ECC Ram won't be able to do anything about it.

agapon 7y ago
It's you who is making the mistake. Non-ECC RAM does not have any protection. Prove me wrong, describe the mechanism.
- blackflame7000 7y ago
  https://en.wikipedia.org/wiki/RAM_parity https://en.wikipedia.org/wiki/RAM_parity
  - rincebrain 7y ago
    From that article: "The SDRAM and DDR modules that replaced the earlier types are usually available either without error-checking or with ECC (full correction, not just parity)."
    - blackflame7000 7y ago
      "ECC (full correction, not just parity)" - meaning byte level parity is standard whereas a cache line checksum is extra.
posix_me_less 7y ago
This goes against all available information on ECC on the internet. Source?
- blackflame7000 7y ago
  https://en.wikipedia.org/wiki/Parity_bit https://en.wikipedia.org/wiki/Parity_bit Furthermore, there is error correction at the chip level. I think a fitting analogy is like this: A single-engine airplane might seem much more dangerous than a dual engine airplane, but most single-engine airplanes have dual fuel pumps, dual ignitions sources, and additional auxiliary devices sharing the same engine body. Will it ever be as safe as a dual engine plane, no, but it's not as dangerous as having no failsafes.
  - tjoff 7y ago
    From the linked article: Modern RAM is believed, with much justification, to be reliable, and error-detecting RAM has largely fallen out of use for non-critical applications. By the mid-1990s, most DRAM had dropped parity checking as manufacturers felt confident that it was no longer necessary.

agapon 7y ago

It's you who is making the mistake. Non-ECC RAM does not have any protection. Prove me wrong, describe the mechanism.

blackflame7000 7y ago
https://en.wikipedia.org/wiki/RAM_parity https://en.wikipedia.org/wiki/RAM_parity
- rincebrain 7y ago
  From that article: "The SDRAM and DDR modules that replaced the earlier types are usually available either without error-checking or with ECC (full correction, not just parity)."
  - blackflame7000 7y ago
    "ECC (full correction, not just parity)" - meaning byte level parity is standard whereas a cache line checksum is extra.

posix_me_less 7y ago

This goes against all available information on ECC on the internet. Source?

blackflame7000 7y ago
https://en.wikipedia.org/wiki/Parity_bit https://en.wikipedia.org/wiki/Parity_bit Furthermore, there is error correction at the chip level. I think a fitting analogy is like this: A single-engine airplane might seem much more dangerous than a dual engine airplane, but most single-engine airplanes have dual fuel pumps, dual ignitions sources, and additional auxiliary devices sharing the same engine body. Will it ever be as safe as a dual engine plane, no, but it's not as dangerous as having no failsafes.
- tjoff 7y ago
  From the linked article: Modern RAM is believed, with much justification, to be reliable, and error-detecting RAM has largely fallen out of use for non-critical applications. By the mid-1990s, most DRAM had dropped parity checking as manufacturers felt confident that it was no longer necessary.