Question Will larger Allocation Unit Size wear out SSD faster?

[erwin1978]

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.