By: Etienne Lorrain (etienne_lorrain.delete@this.yahoo.fr), May 6, 2021 12:08 am
Room: Moderated Discussions
wumpus (wumpus.delete@this.lost.in.a.hole) on May 5, 2021 9:06 am wrote:
> Even modern disk drives use 4k pages, although I'm sure that has more to do with newer ECC
> algorithms (and the need for their efficiency) than any underlying preference for 4k pages.
I do not think there is any advantage in an "ECC line size" bigger than a very few hundred bytes (and there is disadvantages like latency), the 4 Kb pages of disk drives is due to the FTL, translating the disk LBA to the FLASH address - disk embedded software would like bigger pages to reduce size of the translation table: 1 Terabyte / 4096 = 268435456 descriptors, such descriptor shall contain the FLASH address so around 32 bits, so the table size is 1 Gbyte per Terabyte (expensive).
That is, unless the nVME is a zoned block devices:
https://zonedstorage.io/introduction/zoned-storage/
https://lwn.net/Articles/853308/
> Even modern disk drives use 4k pages, although I'm sure that has more to do with newer ECC
> algorithms (and the need for their efficiency) than any underlying preference for 4k pages.
I do not think there is any advantage in an "ECC line size" bigger than a very few hundred bytes (and there is disadvantages like latency), the 4 Kb pages of disk drives is due to the FTL, translating the disk LBA to the FLASH address - disk embedded software would like bigger pages to reduce size of the translation table: 1 Terabyte / 4096 = 268435456 descriptors, such descriptor shall contain the FLASH address so around 32 bits, so the table size is 1 Gbyte per Terabyte (expensive).
That is, unless the nVME is a zoned block devices:
https://zonedstorage.io/introduction/zoned-storage/
https://lwn.net/Articles/853308/