The consensus of opinion seems to be that you should not defrag SSD hard drives, not so much because it's harmful but because of the different NAND filing system used by SSDs. However, there is still quite a lot of controversy in various forums on this topic. Some say defragging harms it because it unnecessarily reduces the life span. Because SSDs have a finite number of writes, they spread the data evenly and randomly over the whole recording surface to maintain even wear. However, data which is corrupt or no longer serves any useful purpose is not written over, as the SSD can't detect that it is useless. And this tends to defeat the purpose of even wear. Windows 7 TRIM is meant to pro-actively delete corrupt or obsolete data on the SSD, and is set to run by default. However, it only works on single disk installations, and even though running in Windows, is not necessarily being implemented on the hard drive. For TRIM to function the operating system, storage drivers and solid-state drive must all support the TRIM command. This is a link HERE to a PDF article on optimizing SSD storage,and which says among other things: "The principle issue is write speed degradation due to free space fragmentation... " When I bought my first Corsair Force SATA3 SSD a year ago, the computer store told me to use it just like a normal HD. So I had been defragging it for almost a year when I became aware that you shouldn't defrag them. I contacted Corsair Tech Support to query whether I would have done any damage, and this was there reply: "The SSDs we develop will last up to 20 years even if you write more than 20GB of information a day (which is well beyond the normal user). I believe you will replace your system long before you replace the SSD." Does anyone know of any 3rd party software that acts independently and safely, to keep an SSD at optimum performance? Update: The link above for some unknown reason did not work. Have replaced it with correct address.