Word on the street is that OS X performs some sort of auto or on-the-fly defragmenting of files 20mb or less. How do you turn off this feature? I have an SSD drive and thus defragmenting of any kind is completely unnecessary as the drive random access time is minuscule. Additionally, the drive controller deliberately spreads bits around the drive to even out the use of cells of memory so the drive lasts longer. So, defragmenting is actually detrimental to SSD drives and works against their built in algorithms.