Macintosh bootable volumes are supported on the internal 2-port PCI card (part number TSATA) but are not supported on any of the other SATA cards at this time.
A very small number of Tempo-X SATA 4+4 users have reported a condition in which connected drives installed in an external case intermittently do not appear when their computer is booted.
To address this issue, update the Tempo-X SATA 4+4 card's firmware to version 1.0.1 or later by downloading and running the latest Tempo-X firmware updater.