I’ve seen a lot of people say that SSDs eliminate the need to defragment your hard drive. And, these people almost made me second guess myself… almost.
While it is true that SSDs eliminate one reason to defrag, and that reason is that hard drives must waste time moving across platters and physical sectors of the drive. This process is made worse if a file exists in several locations on the drive.
But, as Raxco Software outlined on their blog, that’s only half the story. Essentially, Windows (and Mac does this too), transfers files between locations on the drive. It does so with things called data blocks and erase blocks. These are larger than sectors, because they’re basically the fields for which the data is allocated to be moved to, and the area that needs to be erased.
Well, if a file is fragmented, you’ve got a lot more data blocks, and a lot more erase blocks. So, the SSD has to receive several more requests to edit, move, change the file. That means more I/O activity, and more work.
Bottom line: You may want to defrag less frequently with an SSD, but you probably will still want to do it.