3 ms·

What about error detection and correction? Can it be used with the more fragile kinds of Ram?

by DeathArrow 4y ago

dmoy 4y ago
Yes, but it costs more (in $$ and performance)
- leoc 4y ago
  Is there still a whacking great price premium between ECC and non-ECC memory for desktop, but not server, motherboards? If so then that suggests that there's more going on here than a simple expression of consumer choice.
  - gruez 4y ago
    >Is there still a whacking great price premium between ECC and non-ECC memory for desktop, but not server, motherboards? Yes for both. Price: On pcpartpicker a stick of 16GB DDR4-3200 memory without ECC costs $28.99[2], but the ECC version costs $52.99[1]. Even factoring in that ECC ram comes with an extra chip, it's still 62% more. Performance: using the same links above, we see that ECC ram tops out at 3200 MT/s, whereas for non-ECC you can get 4000+ MT/s. The brand selection is also better, which is critical if you want to get high performance memory chips like samsung b-die or micron E die. [1] https://pcpartpicker.com/products/memory/#b=ddr4&E=1&sort=price&Z=16384001 https://pcpartpicker.com/products/memory/#b=ddr4&E=1&sort=pr... [2] https://pcpartpicker.com/products/memory/#b=ddr4&E=0&sort=price&Z=16384001 https://pcpartpicker.com/products/memory/#b=ddr4&E=0&sort=pr...
    - thulle 4y ago
      > Performance: using the same links above, we see that ECC ram tops out at 3200 MT/s, whereas for non-ECC you can get 4000+ MT/s. The brand selection is also better, which is critical if you want to get high performance memory chips like samsung b-die or micron E die. Notable is that the max speed of 3200 MT/s for ECC is due to that being the fastest JEDEC standard for DDR4, you're not getting the XMP-profiles to run them faster and will have to resort to manual overclocking.
- DeathArrow 4y ago
  I was thinking about doing error correction in software at driver/kernel level as opposed to using ECC RAM. Even though ECC contains the logic of doing error correction in one chip, that doesn't justify double prices.
  - dmoy 4y ago
    > about doing error correction in software at driver/kernel level as opposed I have no clue how that works without significant performance cost
  - toast0 4y ago
    As a sibling said, rhis would certainly come at a huge performance cost. Inline/Inband ECC is showing up again recently, which might be of interest. It comes at a performance cost too, but basically you use regular RAM, and the memory controller issues extra read/writes for the ECC data separately from the rest of the data for a given address. If that gains traction, it could bring ECC to the masses.

What about error detection and correction? Can it be used with the more fragile kinds of Ram?

dmoy 4y ago

Yes, but it costs more (in $$ and performance)

leoc 4y ago
Is there still a whacking great price premium between ECC and non-ECC memory for desktop, but not server, motherboards? If so then that suggests that there's more going on here than a simple expression of consumer choice.
- gruez 4y ago
  >Is there still a whacking great price premium between ECC and non-ECC memory for desktop, but not server, motherboards? Yes for both. Price: On pcpartpicker a stick of 16GB DDR4-3200 memory without ECC costs $28.99[2], but the ECC version costs $52.99[1]. Even factoring in that ECC ram comes with an extra chip, it's still 62% more. Performance: using the same links above, we see that ECC ram tops out at 3200 MT/s, whereas for non-ECC you can get 4000+ MT/s. The brand selection is also better, which is critical if you want to get high performance memory chips like samsung b-die or micron E die. [1] https://pcpartpicker.com/products/memory/#b=ddr4&E=1&sort=price&Z=16384001 https://pcpartpicker.com/products/memory/#b=ddr4&E=1&sort=pr... [2] https://pcpartpicker.com/products/memory/#b=ddr4&E=0&sort=price&Z=16384001 https://pcpartpicker.com/products/memory/#b=ddr4&E=0&sort=pr...
  - thulle 4y ago
    > Performance: using the same links above, we see that ECC ram tops out at 3200 MT/s, whereas for non-ECC you can get 4000+ MT/s. The brand selection is also better, which is critical if you want to get high performance memory chips like samsung b-die or micron E die. Notable is that the max speed of 3200 MT/s for ECC is due to that being the fastest JEDEC standard for DDR4, you're not getting the XMP-profiles to run them faster and will have to resort to manual overclocking.
DeathArrow 4y ago
I was thinking about doing error correction in software at driver/kernel level as opposed to using ECC RAM. Even though ECC contains the logic of doing error correction in one chip, that doesn't justify double prices.
- dmoy 4y ago
  > about doing error correction in software at driver/kernel level as opposed I have no clue how that works without significant performance cost
- toast0 4y ago
  As a sibling said, rhis would certainly come at a huge performance cost. Inline/Inband ECC is showing up again recently, which might be of interest. It comes at a performance cost too, but basically you use regular RAM, and the memory controller issues extra read/writes for the ECC data separately from the rest of the data for a given address. If that gains traction, it could bring ECC to the masses.