On 2/8/2016 9:54 PM, Chris Murphy wrote: > Secure erase is really the only thing to use on SSDs. Writing a pile > of zeros just increases wear (minor negative) but also doesn't > actually set the cells to the state required to accept a new write, so > you've just added a lot more work for the SSD's garbage collector and > wear leveling, so it's going to be slower than before you did the > zeroing. Secure erase on an SSD erases the cells so they're ready to > accept writes. at least one SSD I had, the vendor told me writing a full pass of zeros on it via dd or whatever would completely reset the garbage collection and effectively defrag it. -- john r pierce, recycling bits in santa cruz