Operating System Requirements: Mac OS X 10.4+, Mac OS X Server 10.4+ Description: This software enables the use of Tempo SATA E4P and Tempo SATA Pro ExpressCard/34 (3Gb model) in Mac Pro and MacBook Pro, respectively.
Under macOS, If the driver doesn't load, you may need to go to System Preferences...Security & Privacy panel...General tab, and manually authorize the Sonnet driver and restart.
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.
