6 Replies Latest reply on May 22, 2017 3:54 PM by Intel Corporation

    Delayed audio packets using Intel USB 3.0 driver in Windows 7

    aneves

      Hi Everyone,

       

      I work for a software company who makes audio measurement software. As you can imagine, the reliability of the audio transport is very important to us (and I imagine to other users as well). We discovered that using USB audio devices on a variety of computers would sometimes cause a series of audio packets to be delayed. To the average user listening to music this might be a brief annoying click, if they even noticed it. For us, it is a serious measurement error.

       

      After lots and lots of debugging and testing we narrowed down the issue to any Windows 7 computer using the Intel series 7, 8, and C220 (so far) chipsets which provide USB 3.0. The driver in use for USB 3.0, iusb3xhc.sys, appears to be the culprit. We tried updating the USB 3,0 driver by obtaining the latest driver installer from Intel's website (v5.0.3.42 for the 8 series and v1.0.10.255 for the 7 series) but that did not resolve the issue.

       

      Here's how we came to the conclusion that iusb3xhc.sys was the culprit. We had 2 different machines (one a laptop and one a desktop) both running Windows 7 64-bit which could reproduce this delayed audio packet issue consistently. On the laptop, we upgraded to Windows 10 which includes Microsoft inbox drivers for USB 3.0. We could not reproduce the issue afterwards. On the desktop, we kept Windows at Windows 7 64-bit but installed a 3rd party PCIe USB 3.0 controller card which installs its own driver. We connected our audio interface to the USB port on the 3rd party controller card. We could not reproduce the issue afterwards.

       

      Additionally, I took several traces in Windows using xperf so that I could analyze the failure mode in Windows Performance Analyzer. What the trace showed me was that when this failure occurs it is because the audiodg.exe (the Windows Audio Subsystem) thread performing the output pump is waiting an abnormally long time for a thread which has iusb3xhc.sys in it's stack. I cannot determine exactly what as I do not have Intel debugging symbols (.pdb files) for iusb3xhc.sys.

       

      Could someone from Intel comment on this issue and provide further assitance? Ideally, I'd like to see an updated driver package that resolves this issue. Right now, we are forced to tell customers NOT to buy Intel systems.

       

      Thanks!