Fusion Drive split into dual SSDs! Can I Install Windows 10 Bootcamp?

[HelpMePls]

I have a 2012 iMac 27” with a 1.2TB Fusion drive.

I had Windows 10 Bootcamp running on the Fusion Drive.

I had a great idea - make the iMac even faster with an SSD upgrade!

So I opened up my iMac and took out the 1TB old spinning 3.5” hard drive.

I put a 500GB 2.5” SSD in its place using a 2.5” to 3.5” caddy / hard drive mounting bracket.

I left the 128GB SSD alone.

Having done all this I now have two SSD drives showing up as two separate drives instead of one Fusion Drive.

I would like to install Windows 10 Boot Camp onto the iMac as I had done before, but I’ve discovered no-one really runs it internally - they install it externally. Too late! The 500GB SSD is already inside and I’ve sealed the iMac back together.

But installing Windows 10 Bootcamp on the internal SSD is nearly impossible for some reason still unknown to me.

When I watch YouTube tutorials online showing how to install it to an external SDD - there comes a section of the tutorial where you eject and unplug the external SSD and reconnect it. Well I can’t do that because I have no option to eject the internal SSD!

So it’s quite impossible without a complicated workaround...

I then had an idea of merging the two seperate SDD’s together to create a one Fusion drive with the two SSD’s!

I have tried booting in to recovery and running the “diskutil resetFusion” command and I get an error stating, “Your computer must have exactly 1 solid-state and 1 rotational disk drive”.

Is there a way around this?

Or is installing Windows 10 Boot Camp onto one of the two internal SSDs near possible? Also why’s it so complicated compared to if it was an external SSD instead of an internal SSD?

TIA!

 

[_Kiki_]

it's even more easier than you think, download bootcamp drivers using macOS (on to USB stick), after that remove USB stick and close bootcamp assistant, boot to clean windows installation (DVD or USB stick with Windows) select 2nd ssd drive and click install, when installation is finished you can put back USB stick with bootcamp drivers, install and enjoy!

 

[TheSkywalker77]

“Your computer must have exactly 1 solid-state and 1 rotational disk drive”.

I'm pretty sure it's spitting out this error because you're trying to combine two SSD's. I don't know macOS commands, but there might be one for combining two SSD's into one, or RAIDing them together. I believe you can do that from Bootcamp in recovery mode too, just google it.

 

[HelpMePls]

I'm pretty sure it's spitting out this error because you're trying to combine two SSD's. I don't know macOS commands, but there might be one for combining two SSD's into one, or RAIDing them together. I believe you can do that from Bootcamp in recovery mode too, just google it.

Yes you can’t make a Fusion Drive out of two SSD’s which sucks.

This is the only way to install BOOTCAMP on an iMac with a fusion drive - it’s a pain and I’m not going to do it:

https://forums.macrumors.com/threads/bootcamp-nightmare-groundhog-day.2177433/

The user had to actually open up the iMac, remove the whole logic board to get to the default blade tiny SSD and remove that in order to have Bootcamp recognise the OTHER SSD!

This is the ONLY way to have Windows Bootcamp installed on a iMac with a fusion drive - to manually REMOVE the tiny blade SSD on the back of the logic board and thus “breaking” the fusion drive and making BOOTCAMP recognise it as a “NORMAL drive” like any other iMac without a fusion drive.

Quote: “Well I tore apart my Mac again this evening and pulled out that tiny blade SSD. What do you know.... Bootcamp worked right away flawlessly. Unbelievable. I have spent so much time on this. I guess that's what you get when you mess around modifying your Mac. Lesson learned, make sure whatever you do.... only have one internal drive.”

I just ended up swapping back to the old spinning 1TB hard drive and took out my 500GB SSD. I’ll put it inside another iMac without a built in Fusion Drive. I don’t want to risk pulling apart my whole logic board to get to that little tiny SSD just so I can install Bootcamp. Thanks!

 

[Gromit2021]

Hi, You CAN make a Fusion Drive with an SSD because I've recently done it (Catalina). The Apple requirement is that it's 1Gb or larger, so your 500Gb SSD would fail that requirement.

When I replaced the HDD in my previous 2009 iMac it went in fine and carried on being a Fusion Drive, but this time on my late 2014 iMac it came up with two separate drives, ie the 128Gb Apple bit and the new 1Tb Samsung 860EVO SSD.

Bit of a pain, as I'd preloaded the SSD with the contents of the HDD using CCC, but I had to re-make the Fusion drive which erases everything, then restore the CCC image again. When I used the Terminal command it said something like 'Oh, it's an SSD - that's not standard but it's OK' and went on to make the Fusion Drive. Obviously the benefits of a Fusion Drive are much higher when the other disc is a mechanical one and not an SSD.

As an aside, I noticed TRIM wasn't enabled on the new SSD (it was already on on the Apple 128Gb SSD) so I turned that on manually as well.

As the internal 128Gb drive is only on the SATA bus on my old iMac, there seems little advantage in combining an SSD with it, as the speed of the SSD is much the same as the internal 128Gb drive.

With hindsight I might have left them separate and perhaps used the smaller one for Bootcamp (if possible) but hey ho, it's working fine now and I'm leaving well alone!

 

[Fishrrman]

OP:

Which drive is the Mac OS boot drive right now?

The 128gb Apple SSD?
or
The 500gb SSD that you installed?

My suggestion:
Get a copy of the Mac OS up-and-booting on the 128gb SSD.

Next, "clone it over" to the 500gb SSD using CarbonCopyCloner (which is FREE to download and use for 30 days).

Now, boot from the 500gb SSD (using the Mac OS).
Next, open bootcamp assistant and PARTITION the 500gb SSD so that you have a bootcamp partition on it.
Finally, set up Windows on the bootcamp partition.

Having said that...
Unless there is some reason why you must BOOT Windows natively, the better option is to use "an emulation solution" -- VMWare Fusion or Parallels -- if either of those two will work for you.

 

[mdgm]

I would like to install Windows 10 Boot Camp onto the iMac as I had done before, but I’ve discovered no-one really runs it internally - they install it externally. Too late! The 500GB SSD is already inside and I’ve sealed the iMac back together.

I have run Windows (Windows 7 then free upgrade to Windows 10) on internal HDDs in mid-2011 iMacs since they were purchased. I recently started booting one of them from an external. Booting from an internal is more reliable once it is setup properly. For booting off an external reliably it's advisable to setting things up so that it appears to be an internal drive in the startup options.

The advantage of an external is not risking breaking things by opening up the iMac (On 2012 and later models if the screen is not glued on properly it can fall off and smash which then means an expensive repair with screen replacement). Also over Thunderbolt 1 you can get faster speeds than you would from an internal SATA SSD by using a TB3 NVMe SSD. Considering the SATA HDD is much easier to replace than the blade SSD, this is another reason to consider external.

An internal SSD Is much cheaper than setting up a fast TB3 external boot disk:
mid-2012 iMac -> TB(1/2) cable -> Apple TB2 to TB3 adapter -> TB3 dock -> TB3 NVMe drive. Whilst a TB3 NVMe SSD is faster than an internal SSD it's not a lot faster if using a Mac with TB1.

With software like Winclone you can clone a Windows 10 installation for easy restoration later if needed.

 

[Dogtooth]

Yes you can’t make a Fusion Drive out of two SSD’s which sucks.

This is the only way to install BOOTCAMP on an iMac with a fusion drive - it’s a pain and I’m not going to do it:

https://forums.macrumors.com/threads/bootcamp-nightmare-groundhog-day.2177433/

The user had to actually open up the iMac, remove the whole logic board to get to the default blade tiny SSD and remove that in order to have Bootcamp recognise the OTHER SSD!

This is the ONLY way to have Windows Bootcamp installed on a iMac with a fusion drive - to manually REMOVE the tiny blade SSD on the back of the logic board and thus “breaking” the fusion drive and making BOOTCAMP recognise it as a “NORMAL drive” like any other iMac without a fusion drive.

Quote: “Well I tore apart my Mac again this evening and pulled out that tiny blade SSD. What do you know.... Bootcamp worked right away flawlessly. Unbelievable. I have spent so much time on this. I guess that's what you get when you mess around modifying your Mac. Lesson learned, make sure whatever you do.... only have one internal drive.”

I just ended up swapping back to the old spinning 1TB hard drive and took out my 500GB SSD. I’ll put it inside another iMac without a built in Fusion Drive. I don’t want to risk pulling apart my whole logic board to get to that little tiny SSD just so I can install Bootcamp. Thanks!

Removing the blade SSD does the trick. Had I know I could have saved myself hours of frustration and headaches. I installed Bootcamp Windows on a late 2013 iMac on which I replaced the rotational HD with a 2 TB SSD. I’m running Catalina and Windows 10.