Hi As I known there is no different with Avstream miniport driver in USB 2.0 or USB 3.0 host controller. What USB3.0 Host Controller you used? I guess this should be IRP process problem. Check URB and IRP return code maybe some thing wrong during IRP transfer. ________________________________ 寄件者： Moore Zhang <chinahearing@xxxxxxxxx> 收件者： wdmaudiodev@xxxxxxxxxxxxx 寄件日期： 2012/9/28 (週五) 11:58 PM 主旨： [wdmaudiodev] There is noise in my audio driver with USB 3.0 controller Hi Guys: I happened to find that when I plug in my USB 1.1 audio device in the USB 3.0 controller port, there will be noisy when playing music with WMP. But if plug in USB 1.1 or 2.0 controller port, always fine. I’m prepared to analyze and debug the driver code now, but before that does any guy in this list has similar experience of this issue? Should AVStream audio driver make special process for USB 3.0? Detail info: 1. AVStream USB audio driver. 2. Audio Device: C-Media CM106 like USB 1.1 asic 3. System: Win7 32 4. Scenario: smooth with USB 1/2 controller port; in some USB 3.0 controller port, there is noisy.