SSD manufacturers provide "overprovisioning," often 7% of the available space, that's unavailable to the user but available to the SSD controller. I don't prefer that method only because things tend to get warm inside and I can't use smcFanControl to keep things cool.īTW, another thing to consider is that the relocation of valid data before erasure has to go somewhere. This invokes the Startup Manager and while the connected bootable devices appear in a row, they aren't actually in use. With a Mac, a way to get that is to boot with the Option key down. I'm a Crucial SSD fan and one of their suggestions is to allow some powered up quiet time for GC. While TRIM is a definite aid to the Garbage Collection routines which SSD controllers use, they can, over time get by without it. So there will be no sudden magical fix for a drive slowing down because the SSD controller’s Garbage Collection has previously had to deal with “secretly” deleted files which are still taking up space.Ĭonsidering that your SSD has been in use for quite a while and the contents would need to be reconstructed from scratch (unless you have a clone you could restore from), I don't think you'd need to go that far.
That’s what enabling TRIM is for with non-Apple SSDs.Ī key idea is that the space is flagged as available when the deletion takes place which means TRIM must be running continuously to get full benefit and any such benefit is lost for deletions prior to TRIM being enabled. TRIM is the function built into the OS that tells the SSD the deleted file’s space is erasable but it’s only on by default with Apple SSDs.
Second, the HD and the OS both know about file deletion making the space free, but the SSD controller doesn’t, so when the good stuff is moved prior to erasure, the deleted stuff goes too. First, the minimum contiguous space that can be erased is often larger than what the file occupied so before erasure, all the still good stuff in that space has to be moved somewhere else first. When you delete a file from an SSD, the space needs to be erased first by the SSD controller. When you delete a file from a HD, the space it occupied can be written to immediately.