Getting a USB 3.1 gen 2 (10gbps) PCIe card to work at full speed on either a Z420 or Z440

[SDH]

Interesting.... remember that the 3.x specs include more power over the cables, yet I don't see a power feed into that card to supplement the power coming up from the slot into the card.  This might be a significant issue..... drawing too much power through the card out to devices with the only source being its slot.

Do you have any insight on this?  Remember that the HP Texas Instruments chipset-based USB3.0 card has a supplemental power feed in via a SATA power port built into its top edge.  I worry about the card you show and potential damage to the motherboard. Educate me.... is there now enough power coming up just from that PCIe3 x8 slot to meet 3.1 power standards?

[DGroves]

all i can offer on the usb 3.0/3.1 power settings is that it appears  to still be in flux with many overseas venders selling cards,  chargers , and cables that do not follow the usb spec reguarding power delivery sensing. due to this i recomend staying with name brand products from the major online resellers that have been reviewed

https://www.usb.org/usb-charger-pd

http://www.ti.com/interface/usb/type-c-and-power-delivery/getting-started.html

https://www.cablestogo.com/tech/usb-3-1

[SDH]

Thanks DGroves... I did a bit more research.  Note that the HP Texas Instruments "2x2" card is built to support 4 ports, and that is probably why HP wanted to feed it added power:

I've liked these cards and use them in our Z400/Z600 builds.  This card was specifically engineered by HP to bring USB3 to the ZX00 workstations, but they work fine in the xw generation of workstations also.  They should be placed in a PCIe Gen 2 slot to have maximum USB3 bandwidth, and they use the same TI chipset as the ZX20 workstations have on their motherboards.  Thus, that is a nice source of drivers (which should be loaded only after the card is inserted and powered up with the supplemental power cable).  They work under W10Pro64.  They can be found new on eBay currently for about 20.00 USD without the whole kit, or with the whole kit in the HP box, new, for more.  The fitting of the supplemental power plug onto the card is ensured by getting the whole kit.  Other types of power adapters have needed some carving of the black plastic of the plug end.  I've found the Molex brand SATA power plug adapters from Mouser.com seem to fit best, but buying the whole HP kit is easiest.

This HP card is USB 3.0 (aka USB 3.1 Gen 1) and is rated to supply 4.5W per port, 18 W total (0.9A x 5V x 4), so it gets more than enough power via that power adapter.

The USB 3.1 Gen 2 has higher wattage rating..... up to 5A at 20V each port.  This is where "power delivery sensing" becomes important...... that 100W rating per port realistically won't be used via that no-name eBay card the OP showed us and that card likely is safe to use but one needs to know that there is a potential risk of unregulated wattage draw up from the PCIe slot the card is sitting in, and to not pull too many watts through that card at once.  I agree that finding a quality brand name card with documented power delivery sensing is worth the effort.

[KwadGuy]

The confusion regarding the 3.1 gen 2 card i referenced earlier comes from the (not surprising) mis-information in the first image of the eBay listing. The primary image looks like this:

This is the gallary image for the card that works properly to provide USB 3.1 gen performance on Z420

In fact, the card comes in a brown box (not a colored retail box as suggeted) and it actually looks like this: Note the internal SATA power port, as expected:
USB 3.1 gen 2 card as provided. See the internal SATA power connected at end of card