Parallels 5 CPU usage

Discussion in 'Windows, Linux & Others on the Mac' started by danahn17, Dec 8, 2009.

  1. danahn17 macrumors 6502

    Dec 3, 2009
    I just installed Parallels 5 the other day and it seems to have an abnormally high CPU usage, especially with a process called "prl_vm_app." It gets to the point where the computer runs very slow and very hot (according to iStat, CPU temp is reading 185 degrees F!)

    My computer (13" MBP) has 2GB of RAM, which isn't much (I'm planning to upgrade soon) but I would assume that given this is the minimum requirements Parallel recommends, I shouldn't be having this much of a problem?

    Does anybody know of this problem and any fixes?

    Seems like it was a problem in Parallels 4 but was fixed but haven't read much about it regarding Parallels 5 so i figured i'd ask.

    Thanks in advance!
  2. ayeying macrumors 601


    Dec 5, 2007
    Yay Area, CA
    What version of Windows or Linux is your Virtual Machine?

    Is it running some sort of program within a virtual machine?

    How much ram are you allocating to the Virtual Machine? Video Ram?

    185 deg F is not hot whatsoever. The maximum tolerance temperature is ~217 deg F.

    2GB of ram is a stretch, I'd recommend 4GB if all out possible to run virtual machines. Unless you're on the Air, then you kinda don't have a choice there.
  3. danahn17 thread starter macrumors 6502

    Dec 3, 2009
    Thanks for the reply. :)

    I'm running Windows 7 (32 bit). The aforementioned prl_vm_app process was reaching the high CPU usage values even when idling (it idled anywhere between 40 to 70% !).

    Anyways, I decided to delete the virtual machine and make a new one. That seems to have done the trick; the CPU usage is much lower (idling around 6%) and the processor temp has dropped considerably too.

    So hopefully it will stay that way :) I'm still new to this virtualization thing so we'll see how things go from here on out :) Thanks again!
  4. Freewayjim macrumors regular


    Aug 2, 2008
    Metro Atlanta
    Please explain what you did regarding deleting your VM and making anew one, did you re-install 7?

    I ask because I am running XP and upgraded from Parallels 4 to 5 and XP has been much slower booting and running since then, it slows my whole machine down (uMBP 2.53/4GB RAM), OS X as well. I have not looked at CPU usage yet.

    But if your machine is working "right" please tell me what you did w/regards to deleting & adding the VM, not sure about that.

  5. danahn17 thread starter macrumors 6502

    Dec 3, 2009
    Yes, I did a reinstall of Win 7 (I did not reinstall Parallels 5 though). After the installation, I checked to see if everything was okay and then deleted the old Win7 VM. I found the directions to do that here:

    My machine definitely does seem to behave better since I did the reinstall (it pretty much was unusable on both the Mac and PC side of things before). I would check to see what your CPU usage and see if something seems amiss. Like I said before, the biggest culprit in my case was something called "prl_vm_app."

    Another clue might be the heat and amount of fan noise your computer has. Before, it was really hot and the ran was constantly running and quite audible. I haven't heard the fan much since and the temperature has also dropped considerably.

    Hope that helps!
  6. Freewayjim macrumors regular


    Aug 2, 2008
    Metro Atlanta
    Yes, thank you, that was helpful.

    One question, did you have any issues with the Windows activation/authentication when you re-installed 7?
  7. danahn17 thread starter macrumors 6502

    Dec 3, 2009
    No I didn't. I was a little worried it might have but didn't seem to have any problems. I made sure the other VM of Win7 was not running while I was installing a new Win7 VM though (granted, I don't even know if it is possible to install Win7 while running it haha).

    If it helps to know, I used a full Windows 7 Professional version. It was not a Win 7 upgrade and was not an OEM version.

    I suppose if something happens, you could always give microsoft a call and explain your situation and maybe they would give you a new code or something (although if you have an OEM version, that might not be possible). But hopefully it won't get to the point where you will have to call MS! :)
  8. jtara macrumors 65816

    Mar 23, 2009
    Dunno about Parallels, but for VMWare 3.0 I highly recommend Windows 7-64. There are processor extensions that can be used to reduce virtulization overhead, but ONLY if you are running a 64-but guest. (You do NOT need to run a 64-bit OSX kernel.) Both Win7-64 and Kubuntu-64 run like a champ on my 13" aluminum Macbook with 4GB RAM. I've found that giving the guest 1.5GB is a sweet spot.

    If you can still get the Family Pack (3-license upgrade for $149) it is great deal, and comes with BOTH 32-bit and 64-bit, so you don't have to choose in advance. I installed it on my Macbook, then copied the VM to my dedicated Kubuntu box to run under VMWare Player. Activation was no problem.

    BTW, info on upgrade requirements is highly misleading. You do NOT have to install "over" XP to upgrade from XP. You simply need to have a drive with an installed and activated XP installed in your system at the time you install the upgrade. For example, you can plug in a USB drive with XP, attach it to your VM, and install into a clean VM partition. I think what I did was to attach my VMWare XP partition to satisfy the requirement. (And I also first copied the DVD to an .iso file, and attached the .iso to the VM as the DVD drive. The whole installation took < 1/2 hour this way!)

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