Comment by RulerOf
1 day ago
> cheaper flash like TLC and QLC the drive can go much faster by having free space "pretend" to be SLC
I'm afraid I don't understand how exactly this makes it faster. In my head, storing fewer bits per write operation should decrease write bandwidth.
Of course we observe the opposite all the time, with SLC flash being the fastest of all.
Does it take significantly more time to store the electrical charge for any given 1-4 bits with the precision required when using M/T/QLC encoding?
In theory should be more efficient but in reality it's not. Any gains from 'modulating' efficiency are reduced by having to use very aggressive error correction and also write/read things multiple times (because the error rate is so high). I think QLC needs to do usually somewhere on the order of 8 "write/read" cycles for example to verify the data is written correctly.