depending on the type of interface being used, some s.m.a.r.t.-enabled motherboards and related software may not communicate with certain s.m.a.r.t.-capable drives. for example, few external drives connected via usb and firewire correctly send s.m.a.r.t. data over those interfaces. with so many ways to connect a hard drive (scsi, fibre channel, ata, sata, sas, ssa, and so on), it is difficult to predict whether s.m.a.r.t. reports will function correctly in a given system.