OS: Ubuntu 14.04.1 LTS updated to Ubuntu 14.04.2 LTS

Plugging USB flash drive directly into the notebook computer (USB 3.0 port; not using HUB; ALL USB 3.0 external hard drives always connect at SuperSpeed).

Trying with two USB 3.0 ports (both are USB 3.0) and work fine in Windows as well as Linux (with external USB 3.0 HDDs).

Ports are completely clean and free of dust as are the brand new USB 3.0 flash drives.

Upon plugging a USB 3.0 Flash drive sometimes /var/log/syslog reports:

new high-speed USB device number 5 using xhci_hcd


new SuperSpeed USB device number 7 using xhci_hcd

I get the same results with both ports... however, sometimes I get a lot of "Superspeed" connections in a row, or "high-speed" connections in a row.

Now, to get it to connect at SuperSpeed, sometimes I have to switch ports (there are two) and upon going back to the opposite port it will correctly recognize as SuperSpeed. Upon reconnecting it to the same port sometimes it only connects at "high-speed" (usb 2.0 speeds) ... a few more unplug and re-plug cycles and it connects at "SuperSpeed" again.

Other drives are consistently Superspeed (such as external hard drives, etc).

Anyone have a potential solution to get these drives consistently connecting at USB 3.0 (SuperSpeed) ?

In Windows the USB flash drives work great; very fast read and write speeds on the same ports.

Furthermore, to get them to connect at SuperSpeed doesn't guarantee my "write" speed is fast at all, if that might a clue (READ speed is great, WRITE speed is horribly slow such as 5 to 15 MB/sec write speed).

Note: Originally, I thought installing "libccid" might have helped it to connect at SuperSpeed; but now it appears it is just coincidence.

Edit: Drives are Silicon Power Marvel M70 64GB and Corsair Survivor Stealth 64GB

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