The hidden costs of running Windows on a Mac

The hidden costs of running Windows on a Mac

Summary: Thinking of running Windows on a Mac? You can choose Boot Camp or a virtual machine, but are hidden costs in performance for both options. You might be surprised to find which one is faster.


Here are the side-by-side WEI scores for all systems. The top group shows scores for my Mac Mini; the bottom chart shows the two MacBook Airs.

All of these scores are on a scale of 1-7.9. The color coding is simple, bright green is the best, dark red is the worst, with yellow in the middle. The two MacBook Airs have different CPUs, but both have the same 128 GB SSD and Intel onboard graphics. The default VM configuration sets aside a mere 1 GB of RAM for the VM. For the optimized setup, I increased RAM to 3 or 4 GB.

[Click to enlarge chart]

You can see at a glance that virtualization takes a significant chunk of CPU capability away. On my system, the Boot Camp installation scored 308 MB/s for the CPUCompression2Metric and 470.9 MB/s for the Encryption2Metric, versus 152.5 and 223.0 for the same metric under Parallels. For those two tasks, you’re essentially losing half of the CPU by running in a VM. The difference is even more striking in the two MacBook Airs, where the different CPU models account for part of the gap but the VM adds a further penalty.

Likewise, graphics performance in a VM suffers because Windows is unable to use the native Nvidia or Intel drivers and instead has to pass everything through virtualized graphics adapters. Both VMware and Parallels have decent drivers capable of delivering Aero support with transparency and other effects. All of those effects are smooth when running under Boot Camp, but I can see tearing and jerky movements in a virtual machine. The lower scores reflect the differences accurately

Surprisingly, one area of Windows performance actually improves dramatically in a virtual machine. Look at the difference in performance on the Mac Mini, where the WEI score goes from 5.9 to 6.9. The Random Read score is 1.2 MB/s under Boot Camp but increases to 2.7  MB/s when using Parallels. That’s a huge improvement.

On the two MacBook Airs, you can really see the hit that the Intel graphics take when they’re forced to run using virtual graphics drivers. The penalty is even worse because the VM only has 1 GB of RAM available, whereas the Boot Camp installation has 4 GB to work with. And once again you can see the effects of storage drivers. Under Boot Camp, the 128 GB SSD delivers Random Read throughput of 49.5 MB/s. In a VM, the same score is 182.9 MB/s, a fourfold increase.

In Boot Camp, the SSD in that MacBook Air performs far worse than an SSD should.  By way of contrast, a Samsung SSD in a 2009-vintage Dell notebook earned 130.2 MB/s on that score. The SATA III SSD in the Dell desktop I’m using to write this post scores 209.2 MB/s.

The moral? No matter which way you run Windows on a Mac, you’re going to give something up If you use Boot Camp, Windows will probably get as much as it can from the CPU and graphics adapter, but you’ll pay a performance penalty in terms of hard disk speed. By contrast, virtualizing Windows unlocks the full disk speed, especially with SSDs, but you pay a penalty in CPU and graphics muscle.

Topics: Apple, Hardware, Microsoft, Operating Systems, Processors, Software, Virtualization, Windows

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  • A good article, Ed. But just a few more points to consider

    A quick internet search revealed these WEI score clarifications published when Vista was introduced. (If Ed could update the following for Win 7 machines, perhaps that could be a useful bit of information.)

    A WEI score of 4.0: PCs of mainstream and high-end performance of 2006/2007, with the option of using demanding applications and games. Windows Media Center enables smooth playing and recording of HD video.

    A WEI score of 5.0: PC for demanding usage and for Windows Vista without any limitations. It meets the requirements for video processing, graphics and games needing high PC performance.

    A WEI score of 5.9: The best of 2006/2007 (at the same time as Windows Vista was introduced to the market)

    Any WEI score higher than 6.0, IMO, is useful for determining game rig performance bragging rights.

    As readers can see, Ed's published "Boot Camp" WEI scores indicate a solid Windows experience for dual OS uses of Apple hardware. However, even those "VM" WEI scores suggest a more than adequate performance capability for running MS Office Suite apps.

    Obviously, if a person uses apps in both OS environments on one computer and those apps are able to perform at an acceptable level, than any "performance hit" or cost penalty is irrelevant.

    Also, another point to reiterate is that when running Windows in a VM, the more RAM installed on the host computer, the better. (Personally, I have both a high end late model iMac with 16 GB of RAM and a SSD drive plus a 4 GB MacBook and both machines run Windows in a VM machine quite nicely.)
    • RE: The hidden costs of running Windows on a Mac

      I agree - a very useful article. Well done Ed.
      • I agree

        This is a very good article. I've used Parallels and on a i7 Mackbook Pro it seemed fine to me, but on a Mac Air not so much. Mac Air's are much better than a "netbook" IMO, but they don't have much multi-tasking power. As an all in one, it was fantastic but lacked the power for real hardcore multi-tasking, such as running Windows on the side.
    • RE: The hidden costs of running Windows on a Mac

      @kenosha7777 Your correct. I use VM Fusion 3 and it's not like my native i7-920/SLi with 12 Gig RAM Monsterbut its' good for development and everyday work, and I get the best of all three worlds on one machine.
    • RE: The hidden costs of running Windows on a Mac

      @Ed Bott <br><br>"I have a handful of Windows programs that dont have Mac alternatives"<br><br>You probably meant to say "Mac versions", since there are always "Mac alternatives" to similar programs in Windows.<br><br>It's unfortunate that Windows users don't have the same option to run Mac programs that have no Windows versions (or even Mac OS X itself).<br><br>"Thats a bare minimum of $250 on top of the premium cost you pay for Apples hardware. Its at least $300 if you use commercial virtualization software, and possibly much more if you need to pay for additional licenses for Windows apps."<br><br>That's stretching things a bit. Virtual Box is actually quite a nice free alternative to the other commercial virtualization applications. And since many Windows users already have boxed copies of a newer version of Windows that they bought for their PCs, for many Windows users the price of using their Windows programs on a Mac would be $0 using either Virtual Box or Boot Camp.<br><br>"I looked at these numbers on my late-2009 Mac Mini, with a decent Core 2 Duo"<br><br>You are talking about an older, bottom-end Mac that is only about 1/3 the speed of the current model. If you ran Windows on a bottom-end Dell from 2009 you would not see any speed difference.<br><br>Windows running in a virtualization application does take a minor speed hit (usually not noticeable unless you are using graphics intensive programs). This is because it is running in emulation.<br><br>But Windows running in Boot Camp has no performance hit at all! Windows runs at full speed in Boot Camp just as it would on a similarly configured PC.
      Harvey Lubin
      • Did you actually read this post?

        @Harvey Lubin

        I mentioned VirtualBox in the paragraph before the one you wuote. I even included a link to it. I explained why I didn't choose it. (It didn't support Aero until the version that was released literally three weeks ago.)

        Half of my figures are from NEW 2011 MacBook Airs. The single hottest machine Apple sells right now. And the late-2009 Mac Mini is neither slow nor cheap. It's a very competitive machine, especially after it's been upgraded.
        Ed Bott
        • Okay, ED, what if you replace OSX altogether and run Windows natively.

          How does Windows faire on bare (Apple) metal? How does that compare to and equally-equipped Surface Pro or - more realistically - an OEM Windows machine with comparable hardware?
          M Wagner
      • RE: The hidden costs of running Windows on a Mac

        @Ed, Yes I read your article.

        Your reply misses the points entirely, and responds to things that I did not write. I did not write that the 2009 Mac mini was "slow", only that it is much slower than the current model, which is true.

        But the main points which you seem to have missed are:

        Point: Any virtualization of an OS on any platform (including on Windows PCs) will have a performance hit due to the fact that it is running in emulation, and NOT natively.

        Point: Running Windows and Windows programs in Boot Camp is exactly as fast as it is on a similarly configured Windows PC. It is NOT slower!

        Point: For many Windows users switching to a Mac, the price of running Windows and the Windows applications that they own is $0. Saying that the cost is "a bare minimum of $250" is totally untrue!
        Harvey Lubin
      • RE: The hidden costs of running Windows on a Mac

        @Harvey Lubin

        "For many Windows users switching to a Mac, the price of running Windows and the Windows applications that they own is $0."

        Most windows users have windows via OEM, which is not legal to move to a vm. An incredibly small percentage would have a full retail version.
        • Nope

          Microsoft has clarified that you are allowed to run an OEM license of Windows 7 & 8 on a VM, if you even bother with an OEM license of Windows 8, full retail versions are usually cheaper. You just cannot run it on more than one virtual machine or physical computer without the applicable license.
      • RE: The hidden costs of running Windows on a Mac

        @Harvey Lubin
        "It's unfortunate that Windows users don't have the same option to run Mac programs that have no Windows versions (or even Mac OS X itself)."
        I've been running a PC for well over 20 years, and never have I thought "If only I had a Mac to run this one Mac-only software..."
        Don't mistake my words, I've had many Apple products (Mac Mini, iPad, iPod, and even a quad core Mac Pro). The lack of software seems to only be in one direction. PC software is not lagging behind Mac software by any stretch of the imagination. I've never thought, if only I had a Mac, I could run that software. But the onslaught of Parallels, bootcamp, and other technologies tends to prove the opposite of that concept. Even software that could have been considered within that realm has recently been castrated by Apple themselves (Final Cut Pro to Final Cut X).
        At the same time, I am now left with a Mac Mini that is useless unless I put Win7 on it and give it away, an iPod that is so tied up in iTunes (a walled garden of DRM) that no one wants it for free, and a towering hunk of beautiful aluminum (Mac Pro) that has zero possibilities of upgrade beyond RAM, that left to consider the Total Cost of Ownership for any of it. Oh, about the iPad.. simple, no Flash, less than 20 useful apps out of the countless available, no Office apps (compatible or otherwise), and as of yet hasn't been anything more than a toy or device for consuming media (ala Netflix relegated).
        Also, OSX dejour has gone from good to great to garbage with each subsequent release. Relying on some 'social' form of service (Apple forums) is a complete cop-out from actual paid employees researching true answers. In short, moving from one side of the fence to what Apple zealots consider the greener side, has proven quite the opposite. Get your Sh@# together, and then continue your rants. Otherwise, stay off blogs with your personal bias'.
        • So many false statements here...

          It's tough to figure out where to start, but I will take them in order.

          There are indeed some great Mac Only applications, most of which can be used for repairing Windows hard drives WHEN they fail. Yes, there are windows equivalents of these programs; however, they don't do near as good of a job at fixing the hard drives, even when made by the same company. Let's not look at Apple's office suite vs. Microsoft's suite.

          Now, the real kicker for me is the App Store, you buy a piece of software ONCE and you can LEGALLY install it on up to 5 of your computers. Now, you are going to say, ah, but I have installed it on 5 computers and one got stollen. No problem, simply deauthorize all of your computers and authorize the other 4 again (entering your username and password once on each system) and whatever system you replaced the 5th one with and you can still reinstall it there. No serial numbers, etc. to remember either.

          Final Cut Pro to Final Cut X was indeed a mistake, which Apple has fixed and managed to make even better in the end.

          How is the Mac Mini or Mac Pro tower useless? They can still go online, they can still run Windows, OS X, and virtually any program. The Mac Pro can have the following upgrades (and many more): Hard Drive, RAM, Processor (Make sure it is compatible with the motherboard and OS X though), PCI cards, USB Devices, Firewire, etc. Almost any device will just worked when plugged in, yes OS X MAY have to go online to get a driver or two, but it will work. Macbook Pros can also have similar upgrades performed. I have a Macbook pro running 16GB of RAM and I know I can put in at least a 1TB hard drive, possibly larger if I ever need the additional space, although right now I have a 750GB hard drive, so that is sufficient for my needs.

          iTunes has eliminated DRM on all music, so that argument no longer holds true. There are also tons of programs (free and paid) that will remove iTunes DRM.

          The iPad does have Office compatible apps, look at DocsToGo, Mariner Software, etc.

          You accuse Havey Lubin of personal bias, that is not where the bias is. I am not saying Apple products are without flaws, any product will have them, what I am saying is that you didn't even come close to get anything right in your comment.
          • Windows on Macs

            I have been using VM Ware Fusion since v1.1 in 2008 (or 2007) and never really noticed any performance hit - meaning loosing real world usability or reaction time. (I don't play games).

            I now have an early 2011 MacBook Pro that runs Windows 7 under VM Ware Fusion V6 and I have upgraded i7 quad core 2.2Ghz, 1GB VRAM, 16GB RAM, 960GB SSD and 1TB HDD (in Fusion configuration - DVD drive is now a USB external device) - never a hiccup.
            It just works; is so fast, and can't imagine I'll need anything faster or more responsive. So despite all of the numbers that Ed has posted - in real world usage you just don't notice the performance hit.

            These days the power we have is awesome.

            Regarding the cost - everything has a cost. For me it was the choice of lugging two machines around or one.

            I most definitely have the best of both worlds; and for that - I'm prepared to pay a little extra.
          • I agree with you and Ed

            OSX on an i7 Macbook Pro is fantastic. I have parallels, and can run android, windows, whatever with great performance.
            On my old (2011 I think) macbook air, running Parallels on the side was no bueno. I could do it in a pinch, but it lacked the power to do too many things at once. It was amazing as an all-in-one device though, almost the size of my iPad and I could do anything it seemed, if only one thing at a time, but I use a lot of memory hogging adobe products too.
        • You can run Mac OS X on Windows machines

          It's quite easy to setup with VMWare. It's been doable for at least the past 5 years.
          • Doing so violates Apple's licensing agreement.

            I believe there is a single special use exception.
            The Heretic
    • A good article??? Not even close...


      This is common sense psycho-stupid babble... Special Eddie just whote that running windows in a VM will suffer some performance loss and that you will have to pay for the OS and VM SW (if not using boot camp)... DUHHHHHHHHHH!!!! A potty trained chimp could tell you both of those things and it would have been far more entertaining.

      You know what... that's not a bad idea... Get yerself a chimp outfit Eddie... Considering all the worthless drivel you write, it might seem acceptable if everyone thought it was coming from a potty trained chimp.
      • RE: The hidden costs of running Windows on a Mac

        No I bet you a whooole lot of people don't know that running windows under a vm takes a performance hit. For a lot of people especially fanboys they think running windows on a mac is magical and instant with no cost in any way.
      • You're so busy typing insults...


        That you missed the whole part about running Windows in Boot Camp. WHICH IS NOT VIRTUALIZATION.

        Now please go away before a moderator drops a house on you.
        Ed Bott
      • Your Point Exactly?

        @i8thecat3---Sounds like you choked on a hairball on #3 cat, till you turned blue, and suffered consequent irreparable brain damage to ' whote' a post like this.
        Seriously, what does your diatribe add to the discussion, in terms of making any points at all on a technical plane/basis?