iMac and Windows 10

Discussion in 'Windows, Linux & Others on the Mac' started by randalf72, May 14, 2015.

  1. randalf72 macrumors member

    Apr 25, 2014
    I'm about to place an order for a new RiMac just after the WWDC (on that slight chance a refresh is announced) as my student accreditation expires shortly after so I thought I may as well take advantage. :)

    It's also going to be my opportunity to move away from a dedicated Windows PC, however I still have the requirement to run Windows programs on occasion.

    I'm looking to go for the 512gb SSD option on the iMac so I will require external storage of some form. Possibly in a format that could be connected to a Windows PC in the future if required. the memory is likely to be maxed out as well

    The iMac has to be capable of running Windows 7 and Windows 10.

    I'm not that interested in virtualisation so I'm looking at Bootcamp.

    Is it possible to install Windows on an external Thunderbolt SSD? Can I then point the My Documents folder to be on an external USB3 drive?

    Are there any recommendations as to configuration. i.e. install windows on internal SSD and have all data on external drives?

    How can this be best fitted in with external storage for the iMac? Would I need two thunderbolt drives.

    Any suggestions and/or comments welcome.
  2. kgian macrumors regular

    Jul 17, 2011
    I don't understand why you need an external drive. If you get the 512 SSD you can partition it and install windows 7/8/10 in one partition and osx in the other on the same physical disc.

    If the 512GB ssd is not enough for your data you can add as many external HDDs or SSDs as you like with a usb3 connection. No need to go down the expensive thundebolt route. You can even have all your files stored on a NAS.

    I have an 2011 imac with a 256GB internal SSD with 2 partitions, from which I boot Windows 7 (mostly) and now and then osx.
  3. roadkill401 macrumors 6502


    Jan 11, 2015
    Another thing to consider. Apple has officially stated that ALL NEW MACs will no longer support Win7. The 2014 RiMac was the last mac that has support for Win7. if that is a requirement and you will not consider a VM, then you'd better get your mac ordered.
  4. yjchua95 macrumors 604

    Apr 23, 2011
    GVA, KUL, MEL (current), ZQN
    I run Windows on my external USB 3 SSD all the time and it's silky smooth and fast.

    All you need is a good USB 3.0 enclosure with UASP support, a Windows ISO with an install.wim file in it (ISOs with install.esd file won't work) and time.

    The steps needed are a bit long winded, but I can provide them if you need it (only works for Windows 8 and above though).
  5. azentropy macrumors 68020


    Jul 19, 2002
    Currently only "Supports" Bootcamp running Windows 8 on internal drives. Many have been able to run 7, run 7 for external and even run 10. So I guess it is how far are you willing to go to get 7 or 10 working.

    Just curious why you would be against virtualization? Both VMWare and Parallels run pretty much every OS at close to native speed and offer better features than Bootcamp. For instance I can multiple VMs running Windows 7, Windows 10, various Linux distributions, and even older versions of Mac OS X. And many at the same time when needed. The only thing it doesn't do well with is graphic intensive games and some applications that depend on specific hardware support (my friend uses some audio software that needs direct access and doesn't support the virtual sound card settings).
  6. kgian macrumors regular

    Jul 17, 2011
    I believe 512GB is more than enough for 2 OSs to coexist. No need to go external.

    Or, use windows on the internal ssd and have a second external usb 3 ssd for OSX.
  7. BeatCrazy macrumors 68000

    Jul 20, 2011
    Hi. I'm interested in running Windows 10 (I can wait until official release) in a purely external setup on my Late 2013 MacPro and Late 2014 Mac mini.

    Are these the steps you're referring to? Any chance they will be easier/different once the general release of Windows 10 is out?
  8. yjchua95, May 17, 2015
    Last edited: May 17, 2015

    yjchua95 macrumors 604

    Apr 23, 2011
    GVA, KUL, MEL (current), ZQN
    Those are the steps. They will remain the same for both Windows 8 and 10, because of the use of dism.exe.

    I'll post them again here:
    Connect external drive to Windows VM. You must have a Windows VM in VMware/Parallels/VBox, or a Windows PC. Any existing Windows environment will do.

    Note: If you’re using a 32-bit ISO, your Windows environment used to do these commands have to be 32-bit. And if it’s a 64-bit ISO, the environment has to be 64-bit.

    What you need:
    install.wim file (obtain this from your Windows ISO)

    Open elevated cmd.exe (run as admin)

    Note: All commands aren't case sensitive, including pathway to files.

    Type diskpart
    Type list disk
    Take note of the disk you want to select
    Type select disk 1 (if your disk is Disk 1)
    Type clean
    Type convert gpt (do this and then stop at this point if you're using a drive with a Thunderbolt port. If installing in BIOS-CSM, type convert mbr and then stop at this point if you’re using a drive with a Thunderbolt port)
    Type create partition EFI size=100 (skip if installing in BIOS-CSM)
    Type format quick fs=fat32 label=EFI (skip if installing in BIOS-CSM)
    Type assign letter=S (skip if installing in BIOS-CSM)
    Type create partition primary
    Type format fs=ntfs quick label=W2G (or any other name you wish for label)
    Type assign letter=E
    Type exit

    Open up File Explorer. In your C drive, create a new folder named WIN2GO.
    Put the install.wim file in this folder

    Back in cmd.exe:
    Type dism /apply-image /imagefile:C:\WIN2GO\install.wim /index:1 /applydir:E:\ (this process will take quite a while)
    Type E:\Windows\System32\bcdboot E:\Windows /s S: /f UEFI (use this one for UEFI installation)
    Type E:\Windows\System32\bcdboot E:\Windows /s E: /f ALL (use this one for BIOS-CSM installation)

    Restart your entire Mac. After the chime, hold down Option and when prompted to select your boot drive, select EFI Boot (or whatever else that comes up for a BIOS-CSM installation).

    Proceed installation normally.

    After installation, install Boot Camp drivers. Feel free to trash the VM once you're done too.

    For best results, use USB 3/Thunderbolt. If you don't have USB 3, use Thunderbolt. If you have neither, stick back to the internal drive :)

    Don’t use a USB stick.

    Note: This method involves reformatting the entire external drive.

    For Thunderbolt drives, just boot from the Windows USB installer and install directly onto the TB drive. Windows sees TB drives as an internal PCIe connection. However, you must format the TB drive as GPT first (or MBR if installing in BIOS-CSM).

    CAUTION: Windows can only be installed in UEFI flawlessly on Haswell Macs and later. Ivy Bridge and earlier Macs can only run Windows in BIOS-CSM flawlessly. Attempts to boot a UEFI installation of Windows on an Ivy Bridge or earlier Mac will result in driver issues.

    These steps do not work with Windows 7, as it lacks the dism.exe utility.

    UEFI-compatible Macs:
    MacBook Air (mid-2013 and later)
    iMac (late-2013 and later)
    Retina MacBook Pro (late-2013 and later)
    Mac Pro (trashcan shape)
    Mac Mini (late-2014 and later)

    Long story short, only Macs with PCIe SSDs support UEFI. Non-retina MBPs, along with other Macs not listed above (basically all Ivy Bridge and older Macs), are not UEFI compatible.

    WinToUSB basically does the same thing, but doesn’t always work because WinToUSB doesn’t really take into account between BIOS-CSM and UEFI Macs; it only uses one method for all (which may result in boot failures and other problems).
  9. BeatCrazy macrumors 68000

    Jul 20, 2011
    Thank you!

    Since I'm in no hurry, do you recommend I attempt this now, with an evaluation copy of Windows 10? I assume I could pay to update that to a general release version? Or do you think the final release version of Windows 10 will be available as an easy-to-get, paid ISO?
  10. yjchua95 macrumors 604

    Apr 23, 2011
    GVA, KUL, MEL (current), ZQN
    If you have a genuine installation of Windows 8, you'll get Windows 10 for free.

    You can try using the evaluation ISO, but you must have an existing Windows 8.1/10 environment to perform these commands.
  11. BeatCrazy macrumors 68000

    Jul 20, 2011
    I have a standalone genuine Windows 7 machine. Should I wait to update that to 10, first? Then buy a standalone copy to use for the process you described above?
  12. yjchua95 macrumors 604

    Apr 23, 2011
    GVA, KUL, MEL (current), ZQN
    Hmm. You can just upgrade to the beta of Windows 10 straight away on that, and then use the W10 environment to create the external Windows drive.
  13. BeatCrazy macrumors 68000

    Jul 20, 2011
    Thanks, and one more question (I think this dialog will help many others!):

    Assuming a create a licensed external/standalone/bootable instance of W10, will this work on multiple/different Macs? Assuming of course the Mac meets the UEFI requirement.

    And would this bootable drive be cloneable via CCC? With license key intact? For example, if my first drive goes belly-up, can I activate a cloned version as a replacement?
  14. yjchua95 macrumors 604

    Apr 23, 2011
    GVA, KUL, MEL (current), ZQN
    It will. I always bring my Windows drive (960GB Transcend JetDrive USB 3 SSD) to my workplace, hook it up to my nMP and boot off it. At the end of the day, I take it home and hook it up to my 15" rMBP and also boot off it. It's really easy. You just need to install the appropriate drivers (I've both NVIDIA and AMD Catalyst drivers installed inside it).

    I'm not sure whether CCC can do the job, but I know that WinClone can definitely do it.

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