Windows idle but prl_vm_app at 22%?

Discussion in 'Installation and Configuration' started by Shaddam IV, Jan 26, 2010.

  1. Shaddam IV

    Shaddam IV

    I've been running the VM all day, put the Mac to sleep, woke it up, continue working (often running Mac apps concurrently with the VM) and am beginning to notice a certain sluggishness in the VM.

    Windows 7 says that it's quite idle (1% of CPU being used according to Task Manager). However, prl_vm_app is happily using up 22% of my Mac's CPU (and has been for at least half an hour now). It usually uses about 3-4% when Windows is idle, but not now.

    MB Air, 2 GB Ram, NVidia Graphics card. I'm running 1 VM only which has 832 MB Ram, 128 MB Graphics memory, 3D on, 2 virtual processors assigned to the VM. I generated a problem report in case you fancy having a look. Problem report #2405419.
  2. lehmachr


    prl_vm_app - wtf?

    Me too.
    Snow Leopard, latest update with PD5 build 9310.

    prl_vm_app is using 15-20% with NO activity on my windows VM. Yikes!

    Seems this problem was "fixed" in PD4 but exists to some degree in PD5.
    IMHO a double digit CPU usage at idle is not good behaviour.

    Hope others can share experiences, and we should hear from Parallels too (please).
  3. Shaddam IV

    Shaddam IV

    On my setup this has so far happened once, and only at the end of a very long day during which the Parallels VM ran just fine, and during which I'd put the Mac to sleep several times. If this happens again I'll try to do another problem report which may be of interest to the good folks at Parallels :-D
  4. Tim Peel

    Tim Peel

    This is also happening for me and is starting to affect my XP work quite substantially now.

    I switched an existing VM from my iMac to a new MacBook Pro and now I get the stuttering within the VM and the prl_vm_app process runs between 30 - 60 % whilst doing nothing on my VM.

    Not sure if it does this after waking up my laptop or just after an amount of time. Sometimes I can go unaffected and everything appears to run fine.

  5. broesler


    I am so glad to find this thread because this problem has plagued me for months.

    If Windows XP (SP3) in Parallels Desktop for Mac (4 or 5, doesn't matter) is idle for about 30 seconds, one of my internal disc drives starts running constantly (you can hear it and the Menu Meters show it is writing) and all 4 of my CPU cores (2xDual Core MacPro 2.66Gb) start running at 20% - 40%. The Activity Monitor shows the increased CPU usage and it is the prl_vm_app that is getting all the attention. Unfortunately, nothing tells me exactly what is being written (or read?) to what. All I know is that something intense is going on.

    If I simply click in the Windows XP window, the disc drive stops and the CPUs fall back to minimal usage.

    My concern is that the constant activity of the disc drive is wearing the thing out, so I have resorted to "Pausing" Parallels Desktop if I think I will be away from it for a few minutes (what a pain).

    Does anybody know what is going on?
    Is there anyway to stop it from happening?
    Is there a better solution than "Pausing"?

    Surely, this is not normal behavior (I hope).

    Unlike other posts to this thread, I have not noticed any "slow-down" in the Windows performance - just the constant whirring of a disc drive.
  6. Robert M. Münch

    Robert M. Münch Bit Poster

    Same for me. Beside this damnd MDS OSX thread, prl_vm_app is the 2nd biggest resource hog running.
  7. I-che


    Hi Robert,
    what processes are using CPU on Windows side at this time? Please check Task Manager.
  8. chrisdeckard


    I have this same problem. Task Manager in Windows 7 Professional reports almost no CPU usage (normally at 1%) and no processes are using CPU except for taskmgr.exe and it uses almost none. Under OS X as the host, prl_vm_app constantly uses 20% CPU even when no Windows 7 programs are running.

  9. Shaddam IV

    Shaddam IV

    I've meanwhile gone back to using 1 virtual processor in the VM only (since my MBAir will quickly get hot when I run Mac and Windows programs at the same time, and the Mac will then shut down one of its cores, making everything slow) and haven't had that problem since. Knock on wood.
  10. chrisdeckard


    I changed it to use 1 virtual processor as well and it still uses around 9% constantly. So there is some kind of overhead of about 9-10% for each virtual processor configured.
  11. grayloon

    grayloon Bit Poster

    I have Snow Leopard 10.6.3 with all patches applied. My Parallels 5.0.9344 installation running Windows XP with all patches applied is also experiencing a huge CPU load due to prl_vm_app. I thought Parallels 5 was going to fix this
  12. Michael Kazmier

    Michael Kazmier

    Parallels XP Image eating a full core

    I too have been experiencing this problem since upgrading to Parallels 5. I never noticed it under 4 but now because of this my battery is gone in a little over an hour instead of 4 hours - this has to be fixed.

    I am running OS x 10.6.3, Parallels 5.0.9344 (Revision 558741), Windows XP Pro Version 2002 SP3.

    I have tried running with one or two virtual cpus, no difference. I have changed ram settings (size), no difference. My prl_vm_app runs consistently at 99% cpu when the windows machine is idle???
  13. PatriciaP


    Parallels 5.0 with Windows 7 slows to a crawl

    I have an iMac with 4 GB RAM and am runnning Leopard. All updates for Parallels 5.0, Leopard and Windows 7 have been applied.

    With Windows 7, 64 bit OS running no programs and CPU under 1%, "prl_vm_app" is using over 720 mb of RAM!!! Parallels 5.0 has rendered my machine useless. Nothing moves. I did not have this issue with Parallels 4.0 and XP.

    I have tried every fix that this forum has suggested to no avail. I have tried automatic memory allocation and manual memory allocation. The sluggish/stop behavior of the VM doesn't change. Opening a program in Windows 7 is simply painful. There is no other word.

    This problem is being talked about everywhere. Is Parallels even interested?

    We shouldn't need to run 32GB machines to run Parallels.

    What happened Parallels? Anyone listening?
  14. megavolt17

    megavolt17 Product Expert

    I've replied but my replies make it to the forum <50% of the time. I found I had similar issues listed here until I removed Parallels Internet Security by Kaspersky. I did it because I got tired of some if he Windows 7 weirdness due to the 2009 version not being compatible with WIndows 7.

    I uninstalled Parallels Internet Security and installed Kaspersky 2010. The weirdness went away (network connection issues, etc.) but my system seemed sluggish. Task Manager would show 1-3% CPU use, Mac side would show Parallels was using 32% CPU on overage.

    I removed KIS 2010 and noted the Windows system was faster, and the Mac side only showed 1-5% Parallels CPU use. Task Manager still showed 1-3% CPU use. I did a Google search for PC Antivirus CPU use and stumbled into a few reviews. To my surprise Symantec client did well for memory use, CPU use and actually did very well in virus tests. I downloaded it and installed it on Windows 7.

    CPU use by Task Manager 1-5%, CPU use of Parallels from the Mac side show it to be only 2-5% range. No Windows 7 weirdness. Windows 7 seems ALMOST as fast as without an antivirus program, and my Mac runs the same now if Parallels is running Windows 7 or not running at all.

    I believe there is a demo available (I get Norton or McAfee free from work). Be sure you remove all virus programs and reboot prior to installing a new antivirus program. They don't play well together!

    When there is an update to Parallels Internet Security I will likely give that a try. I like Kaspersky's interface better and have had issues with NAV years ago. Not really a valid reason to avoid a product, but experimenting is part of the fun of having a computer!
  15. Lorenzo S

    Lorenzo S

    Same here

    Well I can only join the club. iMac 27", intel i7 quad core, official XP with all updates and prl_vm_app eating from 12 to 60% CPU while machine is doing absolutely nothing!! The disk is always rattling so read/write access is being done. The mac itself is not doing anything. This is happening ever since v4 and it is terrible. I can't possibly think of anything the tool is doing, causing 1) this instable CPU jumping, from 12 to 22 to 10 to 66% etc etc!

    I was planning on submitting a support request but apparently we have to pay to be entitled to support solving bugs, THEY made! I guess it is the new business model. THe Ferengi would be jealous about it.

    So here`s the sample process: Seems like a lot of unnecessary looping is going on here! VM has 2CPUs, got 1.5GB of memory. THIS HAS TO STOP! PLEASE!

    I got build 9443

    Attached Files:

  16. David Morganstein

    David Morganstein

    Parallels VM using 70% of CPU

    Not only am I seeing this problem and finding Parallels 5 to be very sluggish, when I stop the virtual machine and quit Parallels desktop app, my Mac PowerBook Pro's Activity Monitor says Parallels VM continues to run! I have to Force Quit Parallels VM to get the cpu cycles back.

    The MBP has 2Gigs and I let Parallels decide how to use the memory.
  17. OC_Don

    OC_Don Bit Poster

    I've had these things happen over time. Almost each & every one of these symptoms. Sometimes combined. Sometimes single. Not so much with VistaHB, Vista E, Win7, or XP Pro (but it has happened), but in particular, when leaving an Ubuntu vm "idle" for several hours. Strange things always seems to happen. Never repeatable. My way to fix? Create a new vm. From my experience with vm's (more than just Parallels) once a virtual starts misbehaving the only thing to do is save what you need (to external) and blow it away.

    As a mater of operating, I keep all the data files I need on external - either through "shared files" or through USB connection. (Actually I use both. TimeMachine does a nice job of backing up the shared folders data.) When I create a file in a vm, I *always* "Save As ..." to a shared folder or external drive. At any given moment, I can destroy the vm. Usually I will also can the vhdd, but occasionally I will save it and subsequently add as a 2nd (or 3rd or 4th or ...) data drive. But since I keep my files outside of the vm, this is not usually necessary.

    I know this is probably not what you want to hear, but when it comes to a misbehaving vm, just how can it be fixed? Some subtle situation has developed in a particular instance between the guest os, the host os, Parallels virtualization and possibly virtualization support in the chip!. And, where would one start looking for the problem? Parallels? Guest OS? Host OS? (Just because its a Parallels vm doesn't mean the problem is there. I have not found VMWare or VirtualBox to really be any more stable. If you have, then perhaps...) And then what? Would you really expect someone somewhere to look for the problem and develop a patch, when creating a new vm "fixes" the problem.

    From what has been said I see multiple symptoms that may not be related to a single problem. One common theme seemed to be with the Mac going to sleep and waking up over time. However, unless you can repeat any problem such that an engineer can also repeat the problem in a test environment so he/she can analyze the interactions between the Parallels software, the guest os, the host os and the chip virtualization support, expecting someone in Parallels to "fix" the software based on the descriptions of the above symptoms is unreasonable. Providing a diary of the events (programs running, what activities were going on) that occurred over time before the symptoms began to manifest themselves would certainly help. But even then, to write specific patch and test it, well...

    One thing that has help the stability my VistaHB vm is that I disabled screen saving and created a "Parallels" power options script that has everything either "Disabled" "Never" and "Off". I did see significant improvement in NOT encountering problems like those above. Also I run a background networking program (in the vm) so that there is continuos work going on so nobody goes to sleep (only the Mac screen saver and screen display timeout are set). While not feasible for battery op devices, it did help on my iMac (reference to iMan entries above.) As was noted above, there seemed to be something going on with the mac sleeping and waking up. Remember the host os may also go to sleep and wake up. And somehow Parallels is supposed to coordinate activities between the 2 and their use of the cpu. (I mean I know I've got problems when my wife and kids sleep and wake up at different times :cool:

    As for the Ubuntu vm, I start it up, use it and then shut it down. I know I don't like this, but leaving Ubuntu idle in Parallels on the iMac is worse. With with vm's, if they start up a work for "a while", there really is no problem to "debug". But when some where down the line, symptoms like what you speak of start up, at that point forget it. Blow it away. Trying to fix it, I've found to be useless. Putting in trouble tickets without logs covering hours and not being able to demonstrate a repeatable problem is not going to accomplish anything either.

    BTW, I am not with Parallels, but do have a lot of experience with vm's and debugging software.
    As such, my $20 worth.
  18. Dennis Wahlgren

    Dennis Wahlgren

    prl_vm_app isn't using much CPU on my system (2.4 GHz iMac, 4 GB RAM) but it sure does hog a LOT of memory. I'm constantly getting Growl notifications about pageouts to virtual memory. Then after quitting Paralells, prl_vm_app doesn't just quit. It slowly peters out. The memory use drops bit by bit, and after a few minutes it finally goes away. I have no idea if that's normal but all these page-outs and heavy use of virtual memory don't seem right to me. At the very least I had to turn off the sound alerts for pageouts in my Memory Stick app, as they were driving me nuts.
  19. John Featherstone

    John Featherstone

    pri-vm_app (hogs cpu and ram)

    I'm having the same problem under parallels 6.0.11. I'm using WinXp as my VM, and have an early 2008 MacbookPro 2.4 ghz with 4 gig of ram.

    My machine heats up the processor gets (very) hot, and (when gaming) the controls get sluggish, and the game slows to a crawl, movement "stutters" (stops and starts). Under normal applications (like browsers itunes and other applications), I get the "spinning rainbow ball" and dialogue boxes that tell me the "application is unresponsive."
    When I close Parallels out, and reboot, it runs better.

    I'm not any happier with my imac with the same cpu and ram configuration running VMware fusion. Same thing happens there too.

    Earlier versions of both applications were less problematic.
  20. David Morganstein

    David Morganstein

    MBP i7 80% cpu usage

    I'm using the latest v6.0.11822 and continue to see the same thing (see my July 23 post). I quit the VM and Parallels and yet the Parallels VM continues to run according to Activity Monitor.

    After putting the laptop to sleep and re-activating, PVM can eat 80-100% of the CPU cycles. I have to force quit.

    It's been reported by many. Sure would like you guys to fix this.

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