macOS High Sierra has introduced User-Approved
Kernel Extension Loading. For additional information on this update,
FreeBSD driver for ExpressSAS SAS/SATA host adapters. To use this
driver, download this file to your computer, extract the files, and then install it. Additional instructions are available in the ExpressSAS Host Adapter Installation and Operation Manual.
Archived 12Gb GT ExpressSAS® SAS/SATA HBAs Downloads