Learned some interesting info concerning defragmentation in an IT session today. An excellent article is at http://www.thewindowsclub.com/disk-defragmenter-windows
but some quick comments that may be of interest follow:
In Windows 7, Microsoft had turned off defragmentation for Solid State Disks, although in my own instance, it seemed to fail to notice the SSD and ran defrag on a regular basis. In Windows 8 the tool has undergone a change into a general disk optimization tool and apparently it is enabled by default for SSDs.
By default, the Windows defrag tool only defragments files smaller than 64 MB, for according to Microsoft’s benchmarks, fragments of this size, which already consist of at least 16000 contiguous clusters, have a negligible impact on performance. As our image/video file sizes get larger, this may become a consideration.

