USB WLAN adapter causes 100% CPU in host

Discussion in 'Windows Guest OS Discussion' started by PetterW, Aug 26, 2014.

  1. PetterW

    PetterW Bit Poster

    Messages:
    11
    Weird issue today, first time trying out Parallels 10 (moving from Fusion):

    When I plug in a Realtek USB WLAN adapter, specifically a RTL8188CU, OS X Activity Monitor will show between 100 and 200% CPU for my VM process. As soon as I unplug it, back to normal CPU. Nothing shows in guest OS Activity Monitor.
    Tried two different Windows drivers for the unit, without change (can't see why it should...).

    I have a pretty similar adapter which shows as RTL8188ETV in Device Manager. This piece does not exhibit these problems (although CPU util i slightly higher than when running a shared or bridged connection over AirPort - on the order of 15% or so - but that might be a USB thing...?). Also, using an USB Ethernet adaptor presents no issues.

    I have tried this on two different WLAN networks, one that uses certificate-based Windows authentication (the reason why I have to use a dedicated adapter in my guest), and one with regular WPA2 auth - same behaviour.

    Any ideas on how I could troubleshoot this?

    OSX 10.9.4, Parallels 10 build 27695, Windows 7/x64 guest
     
  2. KonstantinO

    KonstantinO Parallels Developers

    Messages:
    37
  3. PetterW

    PetterW Bit Poster

    Messages:
    11
    Thanks, I have a LogMeIn request from support already - will run through that. Thought I should post here as well if there were suggestions or similar experiences from the community. And so I could follow up with an answer, hopefully :)

    Attached to VM - yes that's what it is, if I understand you right. The reason I use the adapter at all is that I need the VM to have it's dedicated adapter attached (in order to be properly authenticated on WLAN).
     
  4. PetterW

    PetterW Bit Poster

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    11
    So, the issue was not solved during the LogMeIn session, but was escalated to second (third?) line with attached system report. I have not heard from it since.
    I just bought a new USB dongle, a Netgear A6100 dual band wifi adapter, and this unfortunately presents the same behavior - the VM is at 115% CPU in the host, but 0% in the guest. The Air's battery is down to just a couple of hours and even the fan is spinning (which virtually never happens otherwise for me).
     
  5. Andrew@Parallels

    Andrew@Parallels Parallels Team

    Messages:
    633
    Hi PetterW,
    Your RTL8188CU device should now work fine with the latest build of Parallels Desktop 10 for Mac.
    Please update Parallels Desktop 10: http://kb.parallels.com/111603 or just use the download link at the bottom of this article.
     
  6. PetterW

    PetterW Bit Poster

    Messages:
    11
    Just tried both the RTL8188CU and the Netgear A6100, still the same unwanted behavior under Parallels build 27712.
     
  7. Andrew@Parallels

    Andrew@Parallels Parallels Team

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    633
    This is not the latest build of Parallels Desktop 10.
    Try to download it here.
     
  8. PetterW

    PetterW Bit Poster

    Messages:
    11
    Right. That was the update that was online at 1600 Europe time :) and that I installed then.
    I downloaded and installed the 28614 now, looks good so far. Thanks, good job!
    Edit: yep, problem definitely seems gone. Great!
     
    Last edited: Oct 28, 2014

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