NewerTech MAXPower 2x 2 USB/eSATA PCIe 2.0 Host Adapter for Mac OS X 10.8.3 and Later and Windows 7, 8, and Later

Works like a charm. Plugged it into my Early 2008 Mac Pro (MacPro3,1) and both eSATA and USB 3 worked great. I did notice that USB 3 was faster (100+ MB/s) than the eSATA interface but I was testing different hardware so it could be a limitation of the eSATA drive dock I was using.Note that I don't believe this card will provide power to USB devices so your device will need to have an external power supply. I have not tested this but am pretty sure this is the case.Bottom Line: Solid product, especially if you're looking for USB 3 speeds.

While the NewerTech support was terrific, the product does not work in a MacPro. Periodically ejects external USB 3.0 connected hard drives. Also, product does not align perfectly in the MacPro's internal card slot so the external facing ports are very close to the edge of the slot opening.

This product doesnt work as advertised, it is not compatible with os 10.10 it was discontinued, by newetech for a new model that doesn't requires a driver, it will make you're mac unstable, reboot unpredictably, and loss data if the usb 3.0 has a external hard drive conected to it, it will unexpectedlly eject flash drives and hard drives, a complete waste of money, and the reseller gm_volume, wont make itself responsible for the misleqding product description on this page, avoid buying from them.

Not as useful as I had hoped. Meh.

It worked great for my 2009 8 core MacPro, until it quit. Very easy to install and fast. After three months of one of the USB 3.0 ports is completely dead, and the other works intermittently.

This was a great purchase. Other cards required removing an internal hard drive from my Mac Pro. This card has worked well so far.

USB3 ports don't work on a 2008 MacPro. Drives keep ejecting themselves randomly. Tried different drives (seagate and wd), tried different PCI slots, tried both OS X 10.9.5 and 10.10.2...

Very easy to install, no additional drivers or power cables needed under Mac OS Yosemite. Installed in a MacPro 3,1.