1 Reply Latest reply on Sep 1, 2015 8:43 AM by joe_intel

    Z97 USB 3.0 devices disconnect on Intel ports




      I asked this question in this thread before, but since no one seems to look at it anymore I make a new thread.


      I have two ASUS Z97-Pro (Wi-Fi ac) mainboards and on both the same problems occur. Every external hard disk drives (and I have tried several different disks) which I connect to any Intel USB 3.0 ports on these boards are disconnected after about 1 - 2 minutes and immediately reconnected. This will continue for about 10 minutes and then sometimes instead of being reconnected Windows gives an error message claiming that the disk needs to be formatted and offering to format the disk. With some disks (Intenso) this happens right away when plugged into the USB 3.0 port, creating such error message once every second until the disk is unplugged again.


      All of these drives work flawlessly on any USB 2.0 or ASMEDIA USB 3.0 port of these mainboards, or on the Intel USB 3.0 ports of other mainboards with the exact same Intel drivers, such as the ASUS P9D WS with an Intel C226 chipset. I'm using Win 7 Pro x64 and the latest Intel USB 3.0 drivers (


      Wi-Fi adapters, such as the Alfa AWUS036H or TP-Link TL-WN8200ND can be installed when connected to an Intel USB 3.0 port, but shortly after an successful installation of the drivers, the device disappears from the device manager. If unplugged and connected to an USB 2.0 port, they reappear immediately and work just fine.


      The UEFI of these ASUS Z97-Pro mainboards have an item called "Intel xHCI Mode" which can be found in the "USB Configuration" menu. The default setting is "Smart Auto". If changed to "Disabled" these problems all seem to disappear. The external USB 3.0 disks work fine (I have not tested the speed yet), and so do the Wi-Fi adapters. However, I have no clue what exactly I am disabling there and what consequences this could have for the system. Also, the same option exists on the ASUS P9D WS and work perfectly fine unchanged (Smart Auto).


      Does Intel have a clue what might be going on here?