Many of us are getting systems with SSD disks. Defragmentation is not really an issue with this type of disk drive because of the technology. However, the technology has limitations in that there are wear considerations. A typical SSD drive (using the MLC technology that is prevalent in our laptops) are only good for 3,000 to 10,000 write cycles. The drives have compensating “wear leveling” algorithms built into the controller to mitigate this.  However, using a defrag tool will cause excessive writes to the disk and will decrease the life of the disk drive.
 
Windows 7 is supposed to detect that a drive is an SSD and turn off the defragmentation tool… however it seems that this is not always the case, so we should look at the Task Scheduler (not Task Manager) and disable the task that periodically runs the defragmentation tool. [more]
 
Now this also raises additional questions which are interesting!
 
1)      What about VM’s running as guest on SSD’s http://blogs.vmware.com/vsphere/2011/09/should-i-defrag-my-guest-os.html

2)      What about Readyboost, Prefetch and SuperPerfetch capabilities of Windows 7

UPDATE:  I am beginning to believe that Windows 7 might actually be detecting the SSD drives and disabling Defrag, Readyboost, etc on these drives. In my case, I can check the task scheduler and Defrag has run as scheduled. HOWEVER, I have another non-SSD drive on my eSATA port (for backup).  This may be confusing the Task Scheduler.