Question Will larger Allocation Unit Size wear out SSD faster?

[watdahel]

When formatting a drive the Allocation Unit Size defaults to 4 Kilobyte. Increasing this will in effect increase average file sizes on the drive. Doesn't that mean larger blocks of data will be moved around during drive wear levelling and cause the drive to fail sooner? For example, if the Allocation Unit Size is set to 2 MB, then a 1 KB text file will occupy the full 2 MB block on the drive. If the text file is modified or erased then the 2 MB block gets rewritten to another 2 MB block or gets erased. On the other hand, with a 4 KB Allocation Unit Size this will result in only a 4 KB block getting rewritten or erased.

 

[igor_kavinski]

Not sure if the SSD firmware can detect how much actual data that needs to be written. But the main problem with larger blocks is slack space rather than writing extra to disk. If the 1 KB file changes to 2 KB, it should write an extra 1KB to that 2MB block. I don't think it will write garbage or zeroes just to fill out the rest of the 2MB block.

 

[00Logic]

From what I have read; matching the cluster size to the SSD's Page Size is actually good for speed and lifespan.
BUT
What they do not specify is this:

Most all SSDs have a pSLC cache nowadays which is ~2x faster at reads and ~6x faster at writes and accepts 1/3rd or 1/4th the amount of data per cell, for TLC and QLC drives respectively.​

That would mean that both the Page and the Erase block size are actually 1/3rd or 1/4th the advertised size...??​

That's IF the Page size is advertised. It can be a mission to find that info.​