Boot Camp Assistant does not recognise second SSD

[cagz]

Hello,

This is a Late 2015 27" iMac with 1TB NVMe SSD and 2TB SATA SSD on it. MacOS is installed on NVMe and I'd like to install Windows 10 in a partition on the SATA drive.

Whatever I did Boot Camp Assistant does not offer an option to install it onto the SATA drive. I tried different formats / partitions on that drive but I get only offered to install Windows on the primary drive (NVMe).

This Apple document clearly states that the Assistant would offer an option if there was more than one internal SSDs. Install Windows on your newer Mac using Boot Camp

When I start Boot Camp Assistant from the terminal it produces a verbose output and it is clearly recognising and scanning both SSDs however in the end it simply says "Found our target disk: disk2" without offering me an option to select disk4.

Furthermore, when I created an ExFat partition on the SATA SSD boot camp assistant recognises this as a Windows installation and offers the option to remove it.

Any experiences with such a two-SSD scenario and how to resolve it ?

 

[chscag]

Welcome to our forums.

Nothing new here.... Windows will only install on the primary boot drive and considers the second drive the same as an external one. With a PC it's possible because you can always switch primary drives via the BIOS menu.

Since Macs have no BIOS but boot from EFI, the Boot Camp Assistant has no way to switch primary drives. There are work arounds to installing Windows the way you want, but we do not approve or disapprove of them.

Do some google searching to find out how. Sorry but we can't be of more assistance with this.

 

[cagz]

Thanks cshcag !

It is odd as Apple document clearly states that this is a supported scenario.

I tried following and it worked fine:
1 - Install Monterey on the second SATA SSD as well.
2 - Boot into it and complete the bootcamp installation on the SATA SSD
3 - Boot back to primary Monterey and delete the OSX related partitions on SATA SSD using Disk Utility.

After this boot camp drivers were not installed, most probably due to the way I rebooted Windows, I ended up installing them manually.

Now dual boot works just as expected.

 

[chscag]

Thanks for posting back. Like I stated above, there are work arounds that can be used. Glad to hear you were successful.

 

[Benzowner]

A bit late, but try this Install Windows 10 on a Mac External Drive 2020