Sandforce might be calculating it that way, but it doesn’t make much sense logically speaking although the calculation is mathematically correct. On most (won’t say all because you never know) SSDs the OP is increased/added by taking off user capacity from the installed flash memory (which usually is in “even”, divisible amounts), not by adding flash memory to a preset capacity. Thin difference.

Responding just to your point of OP always being calculated on the total amount of NAND, that is not true, it is the amount provisioned over the usable space. So it is (1024-400)/400=1.56 or (1024/400)-1=1.56. I do appreciate you keeping me on my toes 🙂

https://renice-tech.com/documents/Definition_of_Overprovisioning.pdf

We appreciate your comments and believe they display the clarification well. Tx!

This is like saying that [imperial] miles are [nautical] miles, even though in different contexts they mean different things. Whenever the chance of mixing them up arises, you have to clarify what you’re talking about, otherwise you only create confusion and room for error when calculations are involved, like in this case.

It is a 400GB SSD. There is 1024GB (16×64) of memory. Let’s stay away from mixing GiB abd GB and leave it as a very simple calculation which has been accepted by the industry for some time now. Thanks ahead!