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.
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.
The Echo ExpressCard/34 Thunderbolt adapter requires Mac OS 10.6.8 or later and supports cards with Thunderbolt technology-aware drivers. Download and install the latest driver to make your card compatible:
Note: Sonnet FireWire 800 Pro ExpressCard/34, and FireWire/USB ExpressCard/34 cards are compatible without additional drivers. For third-party products listed as compatible, please visit those manufacturer's Websites to get the latest, Thunderbolt technology-aware drivers.