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.
This does not happen often, but sometimes the driver caches do not get purged and the new SATA driver does not get loaded correctly from ROM.
Try this:
1) Delete and empty trash for the following file and two directories:
/System/Library/Extensions.mkext (a file)
/System/Library/Caches/com.apple.kernelcaches (a directory)
/System/Library/Caches/com.apple.romextensions (a directory)
Another manufacturer's previously-installed SATA driver may be accessing a Sonnet SATA card in error causing a drive access slowdown. For example, we have seen Fusion D400QR5 performance drop from 200MB/s to under 50MB/s in such circumstances. The solution is to remove the other manufacturer's SATA driver.
