Extending this analogy, you can erase the information you wrote on a page, but if you erase it too many times, the paper will become useless. If we compare the SSD to a book, then the data you store on the media is like writing with a pencil on different pages of a book. As an example: SLC NAND flash is typically rated at roughly 100,000 erase cycles. SSDs are made of microchips storing data in blocks, which are individually able to tolerate a certain number of erase cycles before becoming unreliable. However, when these file systems are used on flash memory media, this becomes a problem. How Does an SSD Work?Ĭonventional file storage systems such as HFS, ext2, UFS and NTFS were originally designed for magnetic disks and so rewrite many of their data structures repeatedly to the same area. However, these features were removed with macOS 10.11 El Capitan. The latter conforms to the DoD 5220.22-M specification. The feature, present in macOS 10.4 to 10.10, offered two options: “Zero Out Data” and “7-Pass Erase”. To reduce the chances of deleted files being recoverable, Apple included a feature called Secure Erase in Disk Utility.

If you want to delete a file forever, you will need to make sure it is overwritten immediately, since a simple “Empty Trash” command will only mark that part of the disk where the file was stored as available.

And it’s true, you should definitely take care when securely deleting data from an SSD. Apple recommends using FileVault instead, which uses encryption to protect your data. With macOS 10.11 El Capitan Apple removed the “Secure Erase” and “Erasing Free Space” features from Disk Utility, saying that they were not needed for a the solid-state drives that are standard in modern Macs because a standard erase makes it difficult to recover data from an SSD.

Erase ssd