Don’t do this unless you NEED to. You don’t even need to secure erase your SSD when you reinstall. The only reasons to secure erase is if there is a drastic speed decrease from either a hard workload or a TRIMless environment which you need fix quickly or if your SSD is acting up. Otherwise TRIM and garbage collection will take care of everything automatically.
Erasing all the data on the SSD:
It is not safe to use DBAN Nuke or similar on SSDs. First, it’s not good for the drive, and second, it wouldn’t work properly anyway. Not good for the drive because it writes to the drive too many times. Wouldn’t work properly because just like the OS, DBAN and similar cannot control where it writes to on the drive. The SSD’s controller is responsible for that, and due to wear leveling algorithms, wouldn’t get you the intended results. DBAN in its current state, is not designed for SSDs. It is used for magnetic drives that have a tendency to retain “images” of previously stored magnetic data. It writes (and sometimes overwrites again) data to the drive, and what is called “secure erase” in DBAN, is different than a “secure erase” command issued by a program designed for SSDs. The secure erase command for an SSD is a command that tells the SSD’s controller to “flush” all of its stored electrons, that it has trapped, from the individual storage cells. It does not write to the drive in any fashion, like a DBAN secure erase does.With an SSD, all you need is to perform a “secure erase” with the proper software.
Secure Erase and NAND:
To learn about how NAND works at a technical level read this: (link)
Tunneling is used to alter the placement of electrons in the floating gate. An electrical charge is applied to the floating gate. The charge enters the floating gate and drains to a ground. This charge causes the floating-gate transistor to act like an electron gun. The excited electrons are pushed through and trapped on other side of the thin oxide layer, giving it a negative charge. These negatively charged electrons act as a barrier between the control gate and the floating gate. A special device called a cell sensor monitors the level of the charge passing through the floating gate.
NAND flash memory uses floating gate MOSFET transistors. Their default state is when the charge is over the 50%. If the flow through the gate is above the 50% threshold, it has a value of 1. When the charge passing through drops below the 50% threshold, the value changes to 0.
0’s are data, 1’s is erase….the fundamental laws of MLC NAND dictate this. You only write the 0’s when you write data to NAND.
So in an erased state the NAND has to report a 1.
Read moreGUIDE: Secure Erase your Solid State Drive (SSD) with Parted Magic