On my system, Checkmate 1.0.4 checks the volume structures and file structures as well as performing Surface scans of all physically attached (FW400/800, USB, Thunderbolt, SATA, and ESATA) drives. To my surprise this includes thumb drives. SMART tests are limited to SATA and ESATA drives due to SMART design and implementation limitations.
To be honest, I have never gotten an accurate handle on how often and when the surface scans are performed but going back through the logs I see where they have been performed. The last surface scan on my FW800 external drive was a week ago.
