USB 3 card drops connection


I bought a usb3 card in sept and used it for the first time yesterday. it is a pcie-usb3-sp with us302p-b on a sticker on the chip side, using driver
I connected a seagate external hard drive and the connection to the drive keeps dropping… It won’t copy a lagrge file and Windows 7 randomely pops up and says it has found the drive. I booted with a linux backup disk and it told me it couldn’t read to different sectors on the drive. I did a sector by sector scan of the disk and it is good.
I plugged the drive into one of the USB 2 ports on my Dell Vostro desktop and it works perfectly, both in windows and in linux. I reseated the card and molex connector withe no help. Any ideas?


Hi Drew,

Thanks for posting your question, I’ll be happy to assist. Because USB 3.0 is so new there can still be incompatibilities between devices. Disconnects like you are describing can be a symptom of compatibility problems or can indicate an issue with hardware like a bad cable.

To isolate where the issue is coming from, we’ll need to isolate the card and the drive. First make sure that the card works with a simple USB 2.0 device like a wired mouse, then if it works and is stable try a USB 3.0 device other than the Seagate drive.

Next try the Seagate in another USB 3.0 host controller (if possible), and try another USB 3.0 cable. Also, try contacting Seagate support to see if they have a fix or a firmware update that might help.

Let me know what you find with the tests, and what you hear from Seagate. If there’s anything else we can do please send the following to

  1. Amazon Order Id
  2. Make and model of computer the pci-e card is installed in.
  3. Make and model of USB 3.0 drive connected to the pci-e card

With these extra details I’ll be able to come up with the best next steps.



I checked with Seagate and they know of no problems with their Backup Plus drive and usb 3 interfacesand have no frimware update for this drive.

I plugged a mouse into your card and didn’t notice any disconnects but I don’t think Windows 7 would show anything on a momentary disconnect. I tried plugging an usb 2 hard drive that I have used for years into your card. It seemed to work ok in Windows but Windows wouldn’t shut down until I unplugged the drive from the card.
My pc is a Dell Vostro 230, a basic 32 bit pc with Intel motherboard and cpu.

The USB standards are well established and the external hard drive is new from one of the largest manufactures. Intel motherboards and cpus are the most common made, so where does the imcompatibilty come from? Perhaps you could tell me which computers and hard drives your card works with? I will email my Amazon order number to you.


Hi Drew,

Thanks for trying those steps and for providing your Amazon Order Id. The USB 2.0 standards are well established but the standards for USB 3.0 are still quite new and being worked out. Our PCI-e to USB 3.0 card uses one of the most common host controller chips available and is compatible with the widest possible array of devices. Here’s a couple of steps to try and narrow down where the disconnect problem is coming from.

If possible try another cable with your Seagate, marginal cables can cause disconnects.

Also, try the Seagate in another USB 3.0 port.

And if possible try another USB 3.0 device in the PCI-e card.

If there’s no way to get any more information about what’s happening, it will be difficult to say with confidence what’s causing the disconnects. We’ll do our best to get your issue resolved, once I know these details I’ll figure out what options we can come up with.


Plugable Technologies


I could keep trying all sorts of combos but life is just too short.

Neither my new, testeed, usb3 drive or my old, proven drive work correctly in your usb3 card but both work perfectly in my built-in usb 2 ports. so the problem is with the card.

You have said nothing about the possibilty of this being a defective card so I will assume that this is just the best your card can do. I will just throw this card away and buy another brand.


Hi Drew,

Sorry to hear that we’re not going to be able to troubleshoot with any other USB 3.0 devices or hosts so the only options left are to try another PCI-e card or to get you a refund. I’ll contact you directly to arrange the details.


Plugable Technologies


I received the new card and it works fine, I am surprised that you didn’t send the newer chipset but this card passed all of my tests.
I will send the other unit back.


Hi Drew,

Thanks for letting me know. I’m glad to hear you are up and running.

Let me know if there’s anything else I can do.