Can I remove the HD completely from my Fusion drive 2012 27" iMac?

[ab225]

I have a 1TB Fusion Drive in a 2012 27" iMac. The drive is loud and slow and I want to use the 128GB PCIe SSD storage (it's a temporary setup and don't need much internal storage). Can I simply disconnect the HD and remove it? Or is the system going to run fans at 100% because there's no HD thermal sensor anymore?

Is there a way to get around this? Like get rid of the HD and leave the sensor? Or do I need to get an SSD adapter for the 3.5 drive and put in a silent SSD with a new sensor?

Thanks

 

[TwoH]

It’ll ramp fans if the SATA cable is left attached to the logic board. Else you’ll be absolutely fine if it’s disconnected

 

[Fishrrman]

Something else you could try, that doesn't involve breaking open the case:
Split the fusion drive.
Once done, ERASE the internal HDD.
Then, just "let it be".
When you power on the iMac, and get to the finder, just "eject" the [empty] HDD.
See if it "spins down".

You'd have to do this each time you booted, of course.
But... it doesn't involve splitting the case...
... which you don't want to do unless you're SURE you can get the job done without breaking anything "in there"...

 

[ab225]

Something else you could try, that doesn't involve breaking open the case:
Split the fusion drive.
Once done, ERASE the internal HDD.
Then, just "let it be".
When you power on the iMac, and get to the finder, just "eject" the [empty] HDD.
See if it "spins down".

You'd have to do this each time you booted, of course.
But... it doesn't involve splitting the case...
... which you don't want to do unless you're SURE you can get the job done without breaking anything "in there"...

This is a good idea. Though I feel like every time I wake it from sleep it will spin up. Also, I'm comfortable tinkering, I got this iMac for just £100 (after my M1 MacBook was recently stolen), so the risk is low.

I might experiment by detaching the drive, leaving the sensor on and seeing what happens.

 

[Nguyen Duc Hieu]

I have a 1TB Fusion Drive in a 2012 27" iMac. The drive is loud and slow and I want to use the 128GB PCIe SSD storage (it's a temporary setup and don't need much internal storage). Can I simply disconnect the HD and remove it? Or is the system going to run fans at 100% because there's no HD thermal sensor anymore?

Is there a way to get around this? Like get rid of the HD and leave the sensor? Or do I need to get an SSD adapter for the 3.5 drive and put in a silent SSD with a new sensor?

Thanks

There is no nVME SSD storage inside an iMac 2012.
I guess it's just a mSATA blade, with Apple proprietary socket.
In that manner, You can just remove both drive and install a bigger 2.5" SATA SSD.