Among the features included in TechTool Pro 4 are S.M.A.R.T. testing to check for impending hard drive failure, email notification if problems are found by the configurable automatic diagnostics routines, optimization/defragmentation, and many other drive and hardware tests to help pinpoint computer problems. One of the most innovative features of TechTool Pro 4 is the eDrive.
An eDrive is a bootable Mac OS X emergency partition containing TechTool Pro. It is created on one of your computer's hard drives without the need to reformat it. If you have problems with your normal startup hard drive volume, you can boot the computer and run TechTool Pro from the eDrive. This allows for recovery and repair without the need to startup from the TechTool Pro CD. This feature is especially useful to notebook users because it negates the need to carry an emergency TechTool Pro CD while traveling. It also eliminates the need for a new CD when the program is updated. This version is the first release on CNET Download.com.