Bizarre CPU problem

Discussion in 'Windows Virtual Machine' started by tblack, Mar 4, 2008.

  1. tblack

    tblack Member

    Messages:
    93
    What could be causing this? Parallels desktop normally uses about 40% CPU just running quietly in the background on my mac, according to Apple system profiler. When I am running a CPU intensive application, the CPU usage of Parallels goes up around 80-100%. That's fine.

    Then for no reason at all, the CPU usage (as indicated by System Profiler) suddenly drops back to about 19%-30%. This is not enough to run any windows application using parallels. Result: application in use falls apart.

    This is really a continuation of an earlier thread regarding Parallels and Dragon NS, which is the app in question here. I can't work out why the CPU just seems to quit periodically when running NS. Even more bizarre: the CPU speeds up again, and the problem rights itself, when I click the mic icon (in NS) off and on again.

    Some sort of conflict between parallels and NS or system problem?

    Any suggestions welcomed.

    Tom
     
  2. dkwehe

    dkwehe Member

    Messages:
    54
    Tom:

    Are you running MS Word or Excel on the Mac simultaneously? I have found that these two seem to be involved when Parallels becomes "not responding" and needs a forced quit. Unfortunately, it's too late by then, and each subsequent application that comes to the foreground also becomes "not responding". A restart is required to get everything going again.

    dkw.
     
  3. tblack

    tblack Member

    Messages:
    93
    I've managed to solve this problem by trawling through old posts dealing with the best methods of setting up Dragon NaturallySpeaking on parallels. The error I have been committing is simple to rectify and the improvement has been fantastic, so let me share it in case anybody else encounters the same problem.

    The trick is not to attempt to connect your USB microphone to the virtual machine, but to connect the USB mike to the Macintosh by selecting it in system preferences> sound, which will make it the default microphone for the Mac - and for the virtual machine, as long as you don't attempt to connect it to the Virtual machine.

    Below is the procedure you should follow, which I have adapted very slightly from a post by webair in the parallels desktop forum on 22 June 2007, which I gratefully acknowledge:

    1. In the Mac OS please go to the "System Preferences" - "Sound" - "Input" - highlight you device in the list (this will make it the default audio input device for Mac).
    2. Set the input volume in the Preference pane so that the microphone input level peaks near the middle of the bar range.
    3. Start Parallels Desktop, choose your VM. In Configuration Editor turn "Autoconnect USB devices" to OFF. [NOTE: in parallels desktop 3.0 Build 5584, you don't seem to get this option; you should choose "connect to the Mac" or "ask me what to do", but if you choose the latter option, whatever you do don't connect the USB mike to the Virtual Machine].
    4. In Configuration Editor, in the Audio tab, choose the Default Audio as the input device.
    5. Run the VM.
    6. Voice settings for Playback and Recording in the Windows XP Control Panel should be left at Intel[r] Integrated Audio.

    [I would double check that your USB mike is not selected in the USB options in the devices menu.]

    If you have already set up a user in NaturallySpeaking, when you try to open it under this new configurations, it will probably ask you to redo your audio settings, which will simply involve doing the volume check and the signal-to-noise check again; this will take a minute or so.

    The result: the bizarre CPU fluctuations that were destroying my dictation accuracy have vanished. Instead of CPU usage hovering around 100% when using NaturallySpeaking, and then inexplicably crashing, CPU usage runs between about 25% and 50%, the Mac runs nice and cool and dictation accuracy is better than it has ever been.

    Tom
     

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