I just read this: http://arstechnica.com/apple/2016/0...-good-and-bad-in-apples-new-apfs-file-system/ After my ssd died from my mp3,1's fusiondrive, I've been thinking how to prolong next ssd's and system's life. In the article it was said that there's no help ftom Trim command to ssd, when ssd doesn't have enough free space. Is ssd always full in fusiondrive? Would it be helpful to make a bit smaller (than the whole storage space in ssd) volume to ssd, which is then used in fusiondrive? Is there a difference how Trim works in 10.10 & 10.11? EDIT: By "full" I don't mean 100% full to the last bit, so you can't write anything to it, BUT something like 90% or 95% full, meaning that Trim command is not effective any more. I have no clue what that percentage really is, so if you have links or insight on this, I'd appreciate!