While looking to add USB 3.0 ports to two servers which had no motherboard ports we tested out two different cards:
Syba USB 3.0 PCIe x1 2.0 Card – 2-Port with internal 19 Pin USB 3.0 Header (Model SD-PEX20139)
Insignia USB 3.0 PCIe x1 2.0 Card – 2-Port (Model NS-PCCUP53)
Performance was both good and comparable for both cards. Both are excellent options for things like backups to external hard drives. We like to format these with ZFS as well so we know the data was written properly … a topic for another blog entry though!
All things considered I prefer the Syba card as it allowed us to activate the USB 3.0 ports on our server cases via the 19-pin USB 3.0 header, while still also providing rear USB 3.0 ports as well. The Insignia does not have the header to do this, but does have the advantage of being available at most BestBuy stores. So if you need something immediately the Insigna is also a good option.
Both come up under FreeBSD 10.1 using the built in xhci driver:
xhci0: <XHCI (generic) USB 3.0 controller> mem 0xdc500000-0xdc501fff irq 16 at device 0.0 on pci1 xhci0: 64 byte context size.
With both cards we were able to max out two external USB 3.0 hard disks (WD Passport Ultra), one on each port, simultaneously getting about 110 MiB/sec on each disk which is the maximum to expect on an external HD.