I have a Mac pro 3,1 (early 2008) and am trying to get it working with the new Drobo 5D and USB 3. I installed a Sonnet Allegro PCIe USB 3.0 card from OWC and the latest drivers from the Sonnettech website which are supposed to support Mountain Lion. A sandisk USB 3 flash drive seems to work but the drobo doesn't show up as a drive. It works fine when I bootcamp into Windows 8 so I don't think there is a hardware problem (using the sandisk sends my Bluetooth magic mouse into fits but that is reported by others). Has anyone got this combination working - do I need to connect the molex power cable to the Sonnet even though Drobo has its own power? Is there another USB 3 option for Mac pro and mountain lion known to work with the Drobo?