SSDs move data that's already on your disk to other places on your disk, often sticking it at a temporary position first. That's what gives defragmenting a disadvantage for SSD users. You’re writing data you already have, which uses up some of the NAND's limited rewrite capability. So, you get no performance advantage whatsoever, but you are using up some of the limited rewrite capability. In short, you should never, ever defrag an SSD. It has no material benefit, and every time you use it, you simply shorten the life span of the drive. PS - I'm a Lead CE who works for one one of the larger SSD and RAM manufacturers on the planet. The design and function of SSD's pay my mortgage.