Help!: My Parallels + Windows 7 is a RAM monster!

Discussion in 'Mac Apps and Mac App Store' started by doxavita, May 28, 2011.

  1. doxavita, May 28, 2011
    Last edited: May 28, 2011

    doxavita macrumors 6502a

    Joined:
    Jul 6, 2010
    #1
    Currently running a 13" 2010 MacBook Pro. (So it's 4GB of RAM)

    When I launch Parallels and it's Windows 7 Virtual Machine, the RAM drops to about 1.28GB left free. From there it starts slowly dropping, and when I check it's already too low: about 23MB left! (after only about 10 minutes) When I try to shut down the VM it takes forever and it seems as if it has crashed...

    Can anything be done about it, or adding more RAM would be my only choice?
     
  2. alust2013 macrumors 601

    alust2013

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    On the fence
    #2
    VMs eat RAM, so upgrading is pretty much your only choice if you need to use Parallels a lot
     
  3. doxavita thread starter macrumors 6502a

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    Jul 6, 2010
    #3
    I just wish there was a way to delay such consumption. How much RAM would I need? (was thinking about 12GB)
     
  4. alust2013 macrumors 601

    alust2013

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    #4
    There isn't, as you are running two OS at the same time. The system needs that much memory, if there was a way to delay memory consumption, then you'd barely need any memory at all. 8GB would be fine, and that is the most you can install in your computer.
     
  5. VTMac macrumors 6502

    Joined:
    Jun 9, 2008
    #5
    I'm assuming you are from a windows background. Repeat after me "free memory is wasted memory". This is how osx and indeed all *nix based oses work. They attempt to maximize the amount of memory used. And thus minimize disk accesses. So free memory being near zero is merely an indicator that osx is doing what it's supposed to do. For your problem you need to look at disk pages in and out. If there is heavy activity then you know it's a memory problem. Free has NOTHING to do with whether you have a memory issue. As to VMs here are a few tips.

    1) always configuration the vm for as little memory as possible. People mistakenly increase ram because they believe that will make the vm run faster. Most times it kills performance. For XP 512meg is normally adequate for productivity apps. For win7 1gig.

    2) This is a biggy DO NOT ENABLE DUAL PROCESSORS in the vm on a dual processor machine. The result will be exactly what you describe. The vm relies on osx for all it's disk and video io. If you give both cores to the vm then the vm will spend all day waiting for a starved osx.
     
  6. doxavita thread starter macrumors 6502a

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    Jul 6, 2010
    #6
    I'm not too knowledgeable regarding all those technical matters you mentioned. But I clearlly saw a slowdown when I tried to shut down the VM at the exact moment the RAM was nearly all consumed. My plan now is to buy more RAM for my iMac, and switch Windows 7 + Parallels there, and just leave my MacBook Pro alone, as it can't handle it properly at the moment.
     
  7. VTMac macrumors 6502

    Joined:
    Jun 9, 2008
    #7
    Well I wish you the best of luck. But you should know you are guessing based on nothing. Free memory is supposed to be close to 0. If programs are using it then it's used as cache for recently accessed files. So while you "clearly saw it" it does not mean what you've concluded. You may yet have a memory problem or you may have totally different problem. The only thing i can say with certainty is free is not indicator of a memory problem.
     
  8. doxavita thread starter macrumors 6502a

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    Jul 6, 2010
    #8
    What would be the proper way to determine if I need more RAM? ( I remember it involved opening up the Activity Monitor, going to the System Memory tab and looking at the page ins and page outs), but how does it work?
     
  9. P Mentior macrumors regular

    Joined:
    Sep 20, 2008
    Location:
    Ohio
    #9
    Here is an explanation for Page-Ins and Page-Outs and what this all means to RAM

    Note: It has been a while since I have done any of this on a Mac as my onlyMac system now is an air and I can't do anything about RAM anyway

    Page-Ins: This is when OSX takes data from the HHD and places it into RAM. This Number gets bigger and bigger the longer you use the system without shutting down or restarting.

    Page-Outs: This is when OSX is Actively using all/most of your available RAM and needs to move data from RAM back to the HHD in order to make room for something else. This data is put into a Page file that acts like virtual RAM but is limited severely by the HHD's speed.

    When do you need more RAM?

    A good method is to look at the amount of page-ins and page-outs and do a little simple math.

    Here is the formula: [Page-outs]/[Page-ins]

    If this number is more than about 10-15% then you might want to look into upgrading your RAM.

    Here is what mine looks like:

    Page-Outs =280KB
    Page-Ins = 2.02GB or about 2,118,123 KB

    So: 280 / 2,118,123 = 0.000132192512 or 00.01%


    I hope this helps you make a good decision as to wether you need to upgrade your RAM or not.
     
  10. VTMac macrumors 6502

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    Jun 9, 2008
    #10
    I couldn't have described it better.
     
  11. Young Spade macrumors 68020

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    Mar 31, 2011
    Location:
    Tallahassee, Florida
    #11
    There are some great posts here; but yea this happens to me as well; what all are you doing while using the program? I only do light web work and my blackmacbook runs fine. Of course. It isn't as fast when the machine isn't running it but still... my machine never slows to a crawl.

    Blackbook, 2.2 4gb here. I would say to go into the settings and configure the virtual system. Allocate 1gb of ram and work from there. Set the settings for speed over visuals and clean up applications on the naitive OS's side as well.
     

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