So I just received the U3X4-PCiE4XE111.
I ordered a U3X4-PCiE4XE111 and a U3X4-PCIE4XE113-Ax but the seller sent two U3X4-PCiE4XE111, one is a used card with a BOM of 1.1.0 and a new card with a BOM of 1.1.1. I am assuming BOM stands for Bill of Materials which should stand for the revision of the card. Here is the 1.1.1 pictured as I have the 1.1.0 currently in the system and they shouldn't be too far apart from each other functionality and chipset wise. If I do take the 1.1.0 card out, I'll update this post with the correct imagery.
Here's a picture of the front and back of the card.
Here's the lspci -nn of the card:
08:00.0 PCI bridge [0604]: PLX Technology, Inc. PEX 8608 8-lane, 8-Port PCI Express Gen 2 (5.0 GT/s) Switch [10b5:8608] (rev ba)
09:01.0 PCI bridge [0604]: PLX Technology, Inc. PEX 8608 8-lane, 8-Port PCI Express Gen 2 (5.0 GT/s) Switch [10b5:8608] (rev ba)
09:05.0 PCI bridge [0604]: PLX Technology, Inc. PEX 8608 8-lane, 8-Port PCI Express Gen 2 (5.0 GT/s) Switch [10b5:8608] (rev ba)
09:07.0 PCI bridge [0604]: PLX Technology, Inc. PEX 8608 8-lane, 8-Port PCI Express Gen 2 (5.0 GT/s) Switch [10b5:8608] (rev ba)
09:09.0 PCI bridge [0604]: PLX Technology, Inc. PEX 8608 8-lane, 8-Port PCI Express Gen 2 (5.0 GT/s) Switch [10b5:8608] (rev ba)
0a:00.0 USB controller [0c03]: Fresco Logic FL1100 USB 3.0 Host Controller [1b73:1100] (rev 10)
0b:00.0 USB controller [0c03]: Fresco Logic FL1100 USB 3.0 Host Controller [1b73:1100] (rev 10)
0c:00.0 USB controller [0c03]: Fresco Logic FL1100 USB 3.0 Host Controller [1b73:1100] (rev 10)
0d:00.0 USB controller [0c03]: Fresco Logic FL1100 USB 3.0 Host Controller [1b73:1100] (rev 10)
As we can see from the above, it's using the same PLX Technology bridge as the StarTech PI40202-6X2B variant. So just by that we can assume that the card works in passthrough and that assumption holds true. I have this card passed-through to both MacOS and Windows. This card uses the Fresco Logic FL1100 chipset which is natively supported on both MacOS and Windows.
I was having some issues with getting the card to work properly with my audio interface which I use as a sound card for Windows (10). I initially thought that the issue was to do with streaming usb data (video, audio) not working however I was proven wrong as my webcam worked fine. I finally linked it to wonky Fresco drivers, the drivers that I used was version 3.8.35514.0. Using the default Windows drivers seems to work better so my suggestion would probably be to not install the Fresco drivers unless you're having an issue with the default ones. After I uninstalled the Fresco drivers, everything seems to be working as it should.
On MacOS (10.15), it was pretty much a breeze. This card works way better than the Renesas card that I had before which doesn't support streaming USB data. This card however seems to support it just fine. I can confirm that my audio interface appears in MacOS and can output audio just fine. I haven't tested it with video but I'm sure it'll be okay.
The card shows up on my system with the ports a, b, c, d mapped to the card respectively from a vertical standpoint with port a being the port closest to the bracket screw mount point.
I did however notice that this card does not seem to support resets in my current system. This means that you are unable to reboot the guest VM by themselves and you have to reboot the host machine. This behaviour is unfortunate but I should be able to live with it considering my MacOS VM has an AMD GPU attached to it and AMD GPUs are known to have the reset bug which is exactly the same thing with this card. It's a minor inconvenience.
I'm not sure if I'll be able to get the U3X4-PCIE4XE113-Ax as the seller has been pretty much ignoring my messages with regards to the wrong card being sent and I'll report back if I do eventually get it.
EDIT:
I checked with the seller and he doesn't have any of the U3X4-PCIE4XE113-Ax anymore. So unfortunately I won't be able to get my hands on it to test. Can't seem to find where to buy it.
For those who are looking for this card though. I believe the Flir website sells it. It should be the following:
https://www.flir.com/products/usb-3.1-host-controller-card/?model=ACC-01-1203