Obviously I didn't make myself clear.
Checkmate is capable of performing
most tests, including a surface scan, on any drive having a physical connection to the computer. This includes physical connections going through hubs.
The exception to this external drive testing is S.M.A.R.T. (Self Monitoring Analysis and Reporting Technology) which is dependent in part on the ATA disk drive connection and although Firewire, USB, and Thunderbolt connections can be used to access external hard drives via a
bridge chip those bridge chips seldom, if ever, access the SMART readings. However, the value of SMART in predicting drive failure is highly questionable while a surface scan has been proven to be the most reliable predictor of impending drive failure and Checkmate
will perform a surface scan on external drives.
What Deskmate can't check are drives connected to the computer via WiFi such as a a Time Machine volume on a Time Capsule.
