VMFusion: 1GB or 2GB of ram?

Discussion in 'MacBook Air' started by lnferno, Jan 13, 2012.

  1. lnferno macrumors 6502

    Jun 19, 2008
    I have ordered a 2011 MBA 13" i7, 4GB RAM, 256 ssd. I've searched the forums and have read about 30 threads on this subject without getting any clear consensus.

    For running VMFusion, what is the ideal configuration in terms of allocated ram and cores for running windows 7 64 bit? I plan on running Office 2010 on the windows side. Should I split the difference and allocate 1.5GB? I can't think of any specific examples right now, but there's always the chance of needing to run other apps in windows, too.
  2. KPOM, Jan 13, 2012
    Last edited: Jan 13, 2012

    KPOM macrumors G5

    Oct 23, 2010
    It's a trade-off between OS X performance and Windows performance. If it's just simple Word, Excel, or PowerPoint files, start with 1 to 1.5GB and see if it works for you. I have 1.5GB assigned to mine, and Quicken 2011 and SoftOffice run well enough for me.

    Also, if you have no plans to run Windows 7 in Boot Camp (i.e. outside the VM), you can save some space by installing 32-bit. 64-bit offers an advantage only with 4GB of RAM or more.
  3. lnferno thread starter macrumors 6502

    Jun 19, 2008
    Thanks for the response and feedback. How many cores did you allocate?
  4. KPOM macrumors G5

    Oct 23, 2010
    I gave it 2 cores, and I believe 192MB of VRAM.
  5. rvinny macrumors regular

    Feb 2, 2007
    I could see this on a quad core chip but isn't the CPU in the Air only 2 cores to begin with?
  6. KPOM macrumors G5

    Oct 23, 2010
    Since the Core i5 and i7 support hyperthreading, they appear to have 4 cores to the operating system.
  7. Jnardis macrumors 6502a

    Jun 2, 2010
    Is there a way to change how much you use for Windows after the install?
  8. VTMac macrumors 6502

    Jun 9, 2008
    You should always reserve 1 physical core for lion. Your machine has 2 physical and 4 logical cores. I would not recommend more than 1 core. (Neither does VMware)

    The goal in allocating memory is to allocate the least necessary where necessary is a function of your apps and workload.

    Never run 64 bit windows unless you have a specific need. It's going to use more memory as a baseline requirement for no benefit.

    1gb is a good staring point for 32 bit win7. Increase in 256mb increments as necessary until you find the balance that works for you.
  9. KPOM macrumors G5

    Oct 23, 2010
    Yes, you can change the RAM or CPU allocation. Note that the VM will detect every change as a "hardware change," so if you change it a lot, you might need to reactivate Windows.
  10. rvinny macrumors regular

    Feb 2, 2007
    Didn't realize I could allocate based on the virtual cores. Good to know, thanks!
  11. kjlake macrumors member

    Jul 15, 2010
    I allocated 1CPU and 1GB of RAM to my Win 7 64-bit VMware Fusion installation and for what I do it works fine. My usage is limited to MS Office products that I do not have a Mac version of (Project and Visio). Of course YMMV...
  12. Mr. Retrofire macrumors 603

    Mr. Retrofire

    Mar 2, 2010
    In VMware Fusion, you can change RAM and CPU cores at will. Windows XP Professional SP3 and Windows 7 Ultimate SP1 do not need a reactivation in this case.
  13. lnferno thread starter macrumors 6502

    Jun 19, 2008
    On a side note, I use OmniPlan2 and OmniGraffle, respectively in lieu of Project and Visio. Those are pretty good alternatives to MS.
  14. dusk007 macrumors 68040


    Dec 5, 2009
    I run Fusion 3.1 and in my experience it is best to just allow it to use all cores. They are shared anyway but there is little benefit in leaving OSX with exclusive cores. If you just use Office and some Apps like it, there isn't any continuous load, and that is really the only reason to allot a limited number of cores. Or if you run two VMs and they do some job that might use up all the resources it can get.
    With word and such just set it to 4 cores. You get max speed in the VM when you use the Windows app and when you don't use it Windows sits usually idle and you still have full speed in OSX or Windows does so little that there is more than enough left for OSX.

    As for memory. I now run 2GB because I have 8 and every once in a while need a bit more. For Office Word + a Browser + some small Windows only app all you need is 1GB. Windows 7 doesn't need as much RAM as OSX it works very well with 1GB if you don't do anything extensive.
    In any case just watch the Task Manager when you do your usual stuff and if there is some cached RAM it is enough that you alloted. If there all the ram is assigned and the swap is used you should add a little.
  15. ZipZap macrumors 603

    Dec 14, 2007
    Well while not the same product, I run Win 7 64Bit on a 512K Parallels VM with 512k video. All on a 2 gig machine.

    Works great and Windows will use virtual memory if it needs more which in the case of the MBA is actually SSD.
  16. maflynn Moderator


    Staff Member

    May 3, 2009
    As others have stated, allocate only one physical core. As for memory, leave enough for OSX ;)

    On some tasks I allocated both physical core to vmware and obviously OSX's performance was horrid - no surprise. As for ram, I found windows to perform adequately with a gig, but it all depends on what you're doing. I run mostly quickbooks.

    Use the activity monitor in OSX to track CPU and ram utilization to better tune your vmware system to be balanced.

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