You could potentially run it that way for the entire life of the drive.
I would replace it with a Caviar Black or 7200.12 at some point though, since external drives are normally very slow.
Originally Posted by gmcrepair
I wouldn't use it for long. One of my clients did this and it shortened her USB HDD life greatly.
It makes no difference to the drive if it is being run directly through sata or USB to sata. Either way, it's the same interface.