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.
Spread Spectrum Clocking is a way to lower electromagnetic interference or EMI. This is important for storage solutions that are required to pass FCC and other agency certifications. All current Serial ATA disk drives implement SSC (some allow you to turn this feature on/off). However, some older SATA drives do not implement SSC. All Sonnet Serial ATA host adapter cards support SSC but will also work with disk drives that do not.
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.