Do partitions on SSDs map to physical addresses? 2

Question

My scenario:

I partition a 250GB SSD drive in half. I fill the 1st partition with OS and data and leave the 2nd one absolutely empty. Does this affect wear leveling of the SSD?

Can partitioning an SSD make the SSD controller not use some memory cells and therefore make wear leveling worse, by overusing certain cells?

In other words, my questions are:

1. On which level does the translation of LBAs to memory cells take place?

2. Does the reservation of LBAs by the OS mean reserving "particular" memory cells, chips or blocks by the SSD controller??

or

3. Do reserved LBAs translate to particular memory blocks, chips or cells? (no matter whether the blocks are located within a single chip or in many different ones)

Answer 1

Partitioning a 250GB SSD in half. I fill 1^st partition with OS and data and leave the 2^nd one absolutly empty. Does this affect wear leveling in ssd?

If you create two partitions and just not use the second one: No.

The data for the first partition will be stored whereever the SSD controller decides it want to store it. That can (and will) use all of the flash cells. The whole disk will wear out equally.

It will not just use the first half of the flash cells for the first partition.

Now if you only created one partition and left the rest of the disk empty (specifically, known empty/unused to the SSD's controller) then it can use this extra free space for additional optimalisations. That will improve performance.

Note that you can archive the same by leaving as much space empty as the second partition is worth. E.g. on a 100GB disk you will get the same advantage with:

50GB in use   50 GB unpartitioned

as with

100GB partition with 50GB not filled with data and with TRIM enabled.

1.In which level the translation of LBAs takes place?

In the SSD. And it is not a hard mapping. LBA sector 1 might point to one flash cell today. But after writing to it it might get stored on another flash cell. This is not visible to the computer. It is only known on the SSD itself.

2.Does the reservation of LBAs by OS, mean reserving "particular" nand cells, chips or blocks by SSD controller?

One a HDD: Yes. On a SSD: No.

Or

3.Do reserved LBAs, translate to particular nand blocks, chips or cells?

Not on SSDs. The SSD will always present the same data when asked for the content of logical block, but the actual storage location might differ.

Think of it as a library.

In clasical (HHD) times a book #1, stored on shellf #1 would always be in the same place. With a SSD this is more akin to treating that as a title and the actual books location will vary. Just as long as that library knowns which book is meant with "book 1 from shelf 1" it does not matter where it is actually located.