how to wipe clean a previously used SSD?

[Miska]

There are some tools for different OS that can run ATA "TRIM" command on the entire drive. This will tell the drive that all the storage blocks are truly unused. This is good starting point, because it also makes sure further wear leveling works correctly.

 

If the OS is/has not been telling the SSD properly with TRIM which blocks are unused, the drive will eventually believe all blocks are in use and contain essential data. This will slow down the drive and cause it to copy data (potentially unused) over to different portions of the drive to keep FLASH cell wearing even.