Molex Connector - Real or Imagined?


Just in case I selected the incorrect listing in the Related Product box, this query is regarding the Plugable PCI Express to SuperSpeed USB 3.0 2-Port Expansion Card for Desktops (NEC/Renesas Chipset).

I’m not clear on whether the device comes with a 5-volt Molex connector attached on the board because the photo of the device shows an empty space for a Molex connector. However, the photo on the device’s carton shows a Molex connector attached to the board. Which photo represents what I can expect to receive when I order the product?

By the way, I’m sitting here with the Plugable product ready to order from Amazon on one browser tab, and a fairly comparable Startech product on another browser tab. I’m inclined to order from Plugable (via Amazon) if I can be sure that I won’t have to solder a Molex connection to the device, otherwise … .

With “itching” trigger finger, I’m looking forward to your reply.




Hi Kate - The molex power was a bit of a hassle - not every system had power cables to spare, connection could be difficult, etc.

When we upgraded to the Renesas μPD720202 chipset with lower power consumption, we were able to design out the molex power connector.

So now it’s a simpler story - no supplemental power to worry about. It’s not there, and you won’t need it.

Thanks for asking!


Thank you for the quick reply, Bernie.

What power output may I expect at the USB ports? I presume Plugable is stepping down the PCIe’s 12v to 5v. The Startech device provides 5v at up to 900 mW per port, but it uses a Molex connector on the board. Will the Plugable device perform similarly with respect to load? My work requires that I use external hard drives that need power from the USB port, i.e., the drives lack separate power supplies.

Another issue: Is the Plugable device controlled principally by firmware, or by software?

Thanks again for your help!


The power output varies a little bit from motherboard to motherboard, which may make the total power across the two powers less than 1.8A, but based on our tests, you’ll always have enough power for two USB bus powered hard disks.

In terms of control – The Renesas μPD720202 chipset does all the heavy lifting in hardware. There is a small firmware component that’s updatable, but we find those updates are rarely needed.

But most of the complexity is in the USB 3.0 software stack, which talks to the hardware via the XHCI interface. On Windows 8, that whole software stack is provided by Microsoft. The μPD720202 chipset and our card are XHCI 1.0 compatible, and work well with Windows 8’s built in stack.

On Windows 7 and earlier, you install the 3rd party stack provided by the chipset maker (Renesas). There is no Microsoft provided stack. The Renesas stack is probably the most mature of all the chipsets.

Hope that background helps. Thanks!