PCI-E 4X Express to USB 3.1 Type C USB-C Dual Port Add on Expansion Card Adapter 10 Gbps

There's nothing out there yet to test the USB 3.1 USB-C speeds with, but I have a USB 3.0 external drive hooked up to a USB-A to USB-C converter and am running thru it. and it runs just fine (like it did thru my USB 3.0 USB-A ports directly on the motherboard.) My MB is a an ASUS Crosshair V Formula. Because the USB-C ports are so tiny, you might accidentally mount the card where they end up hidden by the dividers on your motherboard (in between the card slots). Don't panic. Just loosen the screw & re-align the card correctly and it's no problem. I imagine we'll all run into that occasionally with any USB-C ports on cards like this ... unless they start designing them with a padding on the card to shift the ports out away from the card more. Because it's via a PCIe card (rather than a motherboard chipset), you won't see drives hooked up to it display in the boot-up list, for it gets allocated later. That, too, is understandable and would apply globally to any PCIe card with USB ports. I had trouble reading the tiny driver CD that comes with it, but it's not needed. My Windows 7 Pro immediately & automatically dug up the very latest ASMedia USB3.1 eXtensible driver, etc for it with no problem. I am confident these will work fine at the full expected speed with, for example, a USB 3.1 USB-C NVMe SSD. The shipment was also MUCH sooner than estimated. Much better price than most others, and there are few of same capacity.

Worked until Windows updates for the ASMedia firmware began a war.... at least that's what I think happened. Seller refunded for 1 card... but refused refund for 2 more. The Rosewill RC-509, sold on Amazon, replaced the Dajalon cards and work perfecting with the Windows drivers.