Fill the SSD or not?

[ciakko]

Among the various recommendations on the use of ssd is to not fill it all but to leave at least 25% free space.
Is good advice even for use as cache with primocache?
Thank You
Greetings

[InquiringMind]

The only issue with filling an SSD is that performance may lessen slightly as it gets fuller, since static wear leveling comes into play more often (redirecting a write to a part of the SSD containing data, that data is then relocated - see Increasing Flash SSD Reliability for a fuller description of different wear leveling techniques).

If you are using an SSD for PrimoCache use only, then using the full disk should be fine.

[Kvng]

It is also helpful to leave some unused space on drives that don't support TRIM. In this case, it needs to be free space that is never written to. Use FDISK utility to set up the disk with some unallocated space. The drive will remap and write here when it runs out of erased space and then erase the remapped area as a background operation.