“Back in the days when mechanical hard drives with spinning platters were the norm, you could simply hand your old hard drive to a deserving relative or friend as an upgrade, get a thank you, and call it a day,” Jon L. Jacobi reports for PCWorld. “It’s not so simple with today’s solid-state drives.”
“In many cases, used SSDs simply aren’t as fast as newer ones. The biggest issue in retasking, reselling, or even maintaining an SSD for a prolonged period stems from an inconvenient characteristic of NAND flash memory: Previously written cells must be erased before they can be rewritten with new data,” Jacobi reports. “If the SSD is forced to reuse cells rather than use new ones while storing data, performance will plummet.”
“Simply deleting files and repartitioning and formatting your drive won’t do the trick, however, as those operations take place at levels above where true garbage collection occurs,” Jacobi reports. “In fact, due to the total absence of utilities that force complete garbage collection, there’s only one way to return an SSD to pristine, like-new condition — the ATA secure-erase command.”
Much more in the full article here.