My PC has plenty of onboard USB 2.0 ports, and I have previously added four USB 3.0 ports via one PCIe card. I am out of slots on the mother board, but would like to add an additional USB 3.0 channel because I run a Windows Storage Space configured as a 2-way mirror using two external USB 3.0 drives, and I would like to put those drives onto separate USB channels (aka controllers) for performance reasons.

Obviously, I can expand the number of USB 3.0 ports via an external hub or a cheap USB 3.0 PCIe card with more ports (I have seen as many as 7-ports on one card), but that would keep all of the USB 3.0 ports on the same channel. Its seem to have two options to create an additional USB 3.0 channel:
* I can replace the existing 4-port USB 3.0 card with a card that has two or more "dedicated" channels
* I can replace my existing Gigabit network card with a new card that as USB 3.0 in addition to Gigabit network

The first option tends to be more pricey, and reduces fault tolerance by connecting both USB drives onto the same physical card. The second option is generally a bit cheaper, and increases fault tolerance by putting both drives onto separate USB channels. If one card fails or has a driver issue, the other card my still work so I night still have access to 1/2 of the Storage Space mirror. I decided to go with the second option.

I found three options, organized from lowest price to highest price:
* Syba SD-PEX50100
* SIIG LB-US0614-S1
* StarTech PEXUSB3S3GE

All three of these cards have:
* 1x Gigabit ethernet port
* 3x USB 3.0 (aka USB 3.1 Gen 1, 5GHz Full-Duplex) ports on one channel

All three of these cards have specs that say they support Windows 10, 64-bit.

The Syba and StarTech cards use a SATA power connector, whereas the SIIG card uses an old-school 5-pin Molex power connector.

The Syba and SIIG cards have the USB ports oriented vertically on the backplane connector, whereas the StarTech card has the USB ports oriented horizontally on the backplane connector. I personally prefer the vertical orientation because that tends to make the ports a bit easier to plug and unplug cables.

I have only had one Syba produce, and did not have much luck with it's reliability. However, I have owned multiple SIIG and StarTech products and have never had an issue with any of them.

I decided on the SIIG product, and will come back and update this post with any relevant information after I have it installed.