When not using parallels, does mac regain all memory use?

Discussion in 'Windows Virtual Machine' started by JeromyB, Feb 11, 2011.

  1. JeromyB

    JeromyB Bit poster

    I am using parallels for autocad and set my virtual machine to have 1 of the 2 gig's of memory I've got on my mac. When I stop the virtual machine (windows) and completely close out/stop the parallels program, does the mac regain use of all of the 2 gig's of memory again? Or is 1 gig still set aside for the now inactive virtual machine?

    For some reason, my computer seems like it operates much slower. I have a hatred for everything PC and feel that it may be an autonomous response from my brain. But it brought about some curiosity of the memory situation...

    Thanks for any help!
  2. ronaande

    ronaande Member

    Parallels VMs will use the amount of memory you assign to them while they are in operation. If you assign 1GB, then that amount of memory will be made available for the VM and will count against your available RAM on the Mac side WHILE THE VM IS RUNNING. Once the VM is shut down, that memory is relinquished and once again becomes available for use by other programs. Also, Parallels needs resources of its own, so whenever the Parallels app is running, it will eat some of your RAM and CPU time as well. It is quite meager in usage though, unless you actually have a VM running.

    If you are still unsure, fire up Parallels and turn on your Windows VM, let it load and sit idle for a minute or so. Then, go to "Applications > Utilities" on the Mac side and click on "Activity Monitor." In the lower corner, click on "System Memory" and check to see how much RAM is being used. Make note of that and then shut down your Windows VM. You can keep Parallels running, just shut down windows. Once Windows turns off completely, check your used RAM again. The number should have dropped significantly.

    I can tell you from experience, 2GB of memory on a Mac running a VM is like squeezing a tractor-trailer in an efficiency apartment. Your system will be slow with such a small amount of RAM. It works, but not comfortably. If your system can handle more RAM, it would definitely be worth the investment, particularly since you are running AutoDesk software. It is quite memory/processor intensive and more RAM will do you wonders. You probably are having a lot of paging activity, depending on how many processes/programs you are running...
  3. JeromyB

    JeromyB Bit poster

    Thanks much!


    I completely realize that I don't have enough memory for what I am trying to do, and I only have a 1.83 GHz processor as well. Yikes! It's purely a financial thing. My Mac laptop is about 4 something years old, and I love the thing. It has been extraordinarily reliable for me, but I don't have the funds available to buy a new machine. AutoCAD is available for Mac computers now, but requires a minimum of 3 gig's of memory. My machine will only allow me to upgrade to 2 gig's, which I have done already. So the ONLY reason I have windows or Parallels AT ALL is because of AutoCAD.

    Thanks for the information. I was just curious if the VM would continually eat up memory while parallels is completely off. I know now that I can shut it off when I am not making anything in CAD.

  4. WestonB

    WestonB Bit poster


    You can go here and run a scan on your computer to be certain you can't do a RAM upgrade. I just upgrade to 8 using a dual 2 core duo. Assuming you have a dual core duo, I think you can go up to 4 gb RAM. Hell, it's worth a shot at least to do the scan and it costs between $30-60 to do an upgrade (far cheaper than anywhere else).
  5. LamarL

    LamarL Bit poster

    So let me get this straight, my mac has 8gb of ram. First of all is 8gb of ram a lot? people have told me yes. Second, let's say I allot 2gb of ram to parallels, when I close parallels and I'm just using Mac applications do I get back my 2gb of ram so I have 8 again?
  6. mavidal

    mavidal Product Expert

    Sometimes, you will have ram that is marked as inactive but for some reason the os does not make it available to you again. You can use the following command in terminal to release this inactive ram for use by OSX sudo purge You will be prompted for your password and then in a few seconds, your command prompt will return. close the window with the exit command and your good to go.
    Last edited: Aug 17, 2014
  7. GregorG1

    GregorG1 Bit poster

    My VM will not use the memory that I have apportioned to it. Why not?
    Because I previously had memory issues with my VM, I upgraded my MacBook to 16GB. The configuration suggests I should make 8192 MB available to the VM and this is acknowledged in the task/resource monitor: Installed=8192 MB of physical memory. However, the Total memory allocated is only 2815 MB of which 928 MB (or 32%) is in use, 1242 MB is cached but only 1826 MB is "available" (split 1183 "standby" and 643 "free"). 5377 MB is marked as "available for hardware". Why will it apparently not even try to make use of all that wonderful memory? ;-)

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