Why is parallels or vmware so slow?

Discussion in 'Windows, Linux & Others on the Mac' started by unagimiyagi, Mar 5, 2011.

  1. unagimiyagi macrumors 6502a

    Joined:
    Jun 9, 2009
    #1
    Hello,

    I timed it. Starting windows takes 10 minutes. No doubt my hard drive is being accessed like crazy. Once windows 7 is started, I click Firefox. That takes 60 seconds to launch.

    I have 4gb of ram and a 2.8 ghz macbook pro.

    I have allocated 1 core and 2 gb of ram to the VM. I have a 7200 rpm hard drive

    Is this a disk defrag problem? I thought macs don't need to have that done, and I have over 100 gb of free hard disk space. Would appreciate some help and a definitive word as to why I'm seeing this behavior. Do I need to nuke my hard drive and reinstall everything?

    Thanks
     
  2. balamw Moderator

    balamw

    Staff Member

    Joined:
    Aug 16, 2005
    Location:
    New England
    #2
    You didn't say if it was W7 64 bit or 32 bit. With only 2 GB, 64 bit is quite a bit slower to launch than 32 bit.

    Is anything else taking up RAM on OSX? Once you page in either OS it gets real slow.

    My 2.8GHz MBP performed OK with 2/2 but is much more fluid after I went to 8 GB.

    B
     
  3. SandboxGeneral Moderator

    SandboxGeneral

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    #3
    Your 4GB of RAM is most likely the problem. If you can add more RAM and then allocate about 1GB to the VM, it will run much better. The more RAM the better any computer will perform.

    You need to realize that your hardware is now trying to run two OS's simultaneously and that will put a strain on your resources, especially the RAM.
     
  4. unagimiyagi, Mar 5, 2011
    Last edited: Mar 5, 2011

    unagimiyagi thread starter macrumors 6502a

    Joined:
    Jun 9, 2009
    #4
    Hi, thanks for your quick replies.

    I have windows 7 32 bit. On the mac side, I have firefox open with several tabs and mac office. I am showing over 500 mb of ram available (free +inactive) of my 4 gb total even after running the VM.

    Can you tell me why I would need to go to 8 gb of ram if I am not using all of my 4gb currently?

    Also, if I had 8 gb of ram, I would only allocate 1 gb of ram to the VM? I'm currently allocating 2 gb, so why would I downgrade? I would think that I'd be wanting to allocate 4gb of ram or something.

    If I just boot up the mac, and don't run any mac software and just start the VM alone, it does run faster.

    Thanks!
     
  5. balamw Moderator

    balamw

    Staff Member

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    New England
    #5
    What's listed under VM size, page ins, page outs, swap used?

    B
     
  6. SandboxGeneral Moderator

    SandboxGeneral

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    #6
    What exactly are you doing in Windows through the VM? Does it require a lot of RAM? I think 1GB to 1.5GB of RAM allocated to Windows would be good if you're not using any memory intensive apps.

    Even though you only show 500MB of available RAM, OS/X will start to use the swap file more which is very slow because it runs from the HDD. Plus, Windows will use it's swap file too inside of it's allocated HDD space thus slowing you down farther.

    You can effectively run Windows VM with 4GB of RAM in your computer, you just need to find the right balance of sharing of that 4GB between OS/X and Windows. Adding more RAM will make that task much easier.
     
  7. unagimiyagi thread starter macrumors 6502a

    Joined:
    Jun 9, 2009
    #7
    I have 2.5 million page ins, 297,037 page outs
    Swap is 2.5 gb / 3.0 gb

    Hmm...I just set the VM's ram to 1 gb, down from 2 gb, and everything is smooth again. I'm satisfied with the speed. Boot up is more like 1-2 minutes, and firefox launches in 6 seconds instead of 60. I don't hear the hard drive churning constantly anymore. Setting aside 2 gb actually made the VM slower.

    I also increased the size of the VM to 70 gb, up from 40 gb.

    I am just using firefox in windows at the moment.

    I think that decreasing the RAM allotment to 1 gb, thereby leaving 3 gb for mac os, sped up everything again. That still seems odd to me, but it worked.
     
  8. balamw Moderator

    balamw

    Staff Member

    Joined:
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    Location:
    New England
    #8
    What you are doing in OS X is RAM hungry.

    Spend the ~$100 and upgrade to 8GB. It will make everything smoother.

    1GB for Windows 7 32 is marginal, it will start swapping out if you stress it more.

    B
     

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