Apple SSD Controller Says "Unknown"

[Alvin777]

Hi Apple and Mac friends.

In System Information > SATA Device Tree

It says Apple SSD Controller is "Unknown". It also says:
"No" to both Native Command Queuing and Detachable Drive.

Is it detecting that there is an SSD there? How can it be revived?

Thank you.
God bless, Rev. 21:4

 

[Fishrrman]

Which iMac?
What year made?
What OS is running?

What kind of drive is attached?
Who made it?

 

[Alvin777]

Which iMac?
What year made?
What OS is running?

What kind of drive is attached?
Who made it?

Hi. Thanks for the reply.

Late 2015 5K iMac
macOS Big Sur
2TB Fusion (by Apple)

 

[Nguyen Duc Hieu]

Hi Apple and Mac friends.

In System Information > SATA Device Tree

It says Apple SSD Controller is "Unknown". It also says:
"No" to both Native Command Queuing and Detachable Drive.

Is it detecting that there is an SSD there? How can it be revived?

There is no SATA SSD in your iMac.
There is no T2 chip (to lock SSD) in your iMac => "Unknown"

 

[Fishrrman]

A 2015 iMac with a 2tb fusion drive should have inside TWO drives:
- 128gb SSD (I think it still had the larger SSD back then)
and
- 2tb platter-based HDD

These two drives are "fused together" by the OS so that they will appear as only ONE drive "on the desktop".

But... looking at your original post...
What is wrong?
Does the Mac boot?
Once you're in the finder, does it run ok?

Are you just wondering about the indication you're seeing in System Information?

So long as the Mac boots and runs, again, is there a problem?

 

[Alvin777]

Hi. The Mac et

A 2015 iMac with a 2tb fusion drive should have inside TWO drives:
- 128gb SSD (I think it still had the larger SSD back then)
and
- 2tb platter-based HDD

These two drives are "fused together" by the OS so that they will appear as only ONE drive "on the desktop".

But... looking at your original post...
What is wrong?
Does the Mac boot?
Once you're in the finder, does it run ok?

Are you just wondering about the indication you're seeing in System Information?

So long as the Mac boots and runs, again, is there a problem?

Hi. The Mac can't see the SSD part of Fusion. System Report is seeing it as Unknown (check screenshot above on original post), Disk Utility can't see it nor Terminal.

Is there a way firmware flash this Apple Blade SSD? I've already fresh installed macOS Big Sur but only the hardrive. The SSD has somehow split (possible the last Windows app I used caused it) and it Unknown now by the Apple SSD controller but it's still there it seems.

 

[Nguyen Duc Hieu]

Hi. The Mac et

Hi. The Mac can't see the SSD part of Fusion. System Report is seeing it as Unknown (check screenshot above on original post), Disk Utility can't see it nor Terminal.

Is there a way firmware flash this Apple Blade SSD? I've already fresh installed macOS Big Sur but only the hardrive. The SSD has somehow split (possible the last Windows app I used caused it) and it Unknown now by the Apple SSD controller but it's still there it seems.

What makes you think there is an SATA SSD in your iMac?
You haven't digested this thread thoroughly.
If you had, you wouldn't have beaten around the forum for the same issue.

A list of successful iMac 27" (2012-2019) SSD upgrades

Here you can find and discuss all the collected knowledge regarding upgrading the HDD, blade SSD and CPU of a 27" iMac 2012-2019, as well as a list of performed upgrades. Here is a list of all 27" iMac models subjected in this thread: Late 2012 - 13.2 - MD095LL/A (2.9Ghz i5-3470S, HDD only /...

forums.macrumors.com

 

[Alvin777]

What makes you think there is an SATA SSD in your iMac?
You haven't digested this thread thoroughly.
If you had, you wouldn't have beaten around the forum for the same issue.

A list of successful iMac 27" (2012-2019) SSD upgrades

Here you can find and discuss all the collected knowledge regarding upgrading the HDD, blade SSD and CPU of a 27" iMac 2012-2019, as well as a list of performed upgrades. Here is a list of all 27" iMac models subjected in this thread: Late 2012 - 13.2 - MD095LL/A (2.9Ghz i5-3470S, HDD only /...

forums.macrumors.com

Hi. It’s a 2TB fusion (one hardisj, one Apple Blade SSD- I didn’t remove anything).

 

[Nguyen Duc Hieu]

Hi. It’s a 2TB fusion (one hardisj, one Apple Blade SSD- I didn’t remove anything).

You know why you are ignored? You stick you mind to your own bias.
The "Apple Blade SSD" in your iMac is an nVME blade, not a SATA blade.

Read this post again (you've already read it but didn't understand) and take a close look at every photo in it, the guy has the same iMac as yours, and his description is super detailed.

A list of successful iMac 27" (2012-2019) SSD upgrades

Late-2015 27” retina 5K iMac SSD upgrades I performed the SSD upgrades of both blade and SATA drives this past May. I followed the iFixit guide and also found some videos on the OWC website that were helpful. I found the OWC videos helpful not only with upgrading the drives, but for removing...

forums.macrumors.com

 

[Alvin777]

You know why you are ignored? You stick you mind to your own bias.
The "Apple Blade SSD" in your iMac is an nVME blade, not a SATA blade.

Read this post again (you've already read it but didn't understand) and take a close look at every photo in it, the guy has the same iMac as yours, and his description is super detailed.

A list of successful iMac 27" (2012-2019) SSD upgrades

Late-2015 27” retina 5K iMac SSD upgrades I performed the SSD upgrades of both blade and SATA drives this past May. I followed the iFixit guide and also found some videos on the OWC website that were helpful. I found the OWC videos helpful not only with upgrading the drives, but for removing...

forums.macrumors.com

Hi. It’s ok we’ll figure it out (Apple Blade SSD is AHCI, I wish it was NVME with regular connectors but it's on a PCIe 3.0 bus).

Thanks, Peace.

 

[Nermal]

What shows up in System Profiler under NVMExpress?

 

[Alvin777]

What shows up in System Profiler under NVMExpress?

Hi. It says:

"This computer doesn’t contain any NVMExpress devices. If you installed NVMExpress devices, make sure they are connected properly and powered on."

(This SSD is in a Late 2015 5K iMac, the 128GB Apple Blade it uses I believe is still AHCI. I wonder if this is a software issue? I did the Hardware Diagnostics it says "No Issue" and reset the PRAM 4x, SMC's been reset too)

 

[nbjyo]

Same problem here. Have you fixed it yet?

> To those who say there is no SATA SSD in iMac 2015 (Fusion Driver), you are wrong.

I think the fusion driver solution are using the SSD too heavy cause it broken down in 6 years.
After I upgrade to Monterey 12.1, the broken SSD start to cause system not working properly, like startup very slow, other external SSD won't mount, etc. So I've also searched a lot, trying to find a software solution to disable it completely without lucky. Maybe the physical way to remove or replace it is the only solution. Please tell me if you have find any solution. Thanks

 

[Alvin777]

Same problem here. Have you fixed it yet?

> To those who say there is no SATA SSD in iMac 2015 (Fusion Driver), you are wrong.

I think the fusion driver solution are using the SSD too heavy cause it broken down in 6 years.
After I upgrade to Monterey 12.1, the broken SSD start to cause system not working properly, like startup very slow, other external SSD won't mount, etc. So I've also searched a lot, trying to find a software solution to disable it completely without lucky. Maybe the physical way to remove or replace it is the only solution. Please tell me if you have find any solution. Thanks

Hi, sadly not yet. It must have overheated coz' I didn't use the tools for it that macOS uses. I hope when I do the SSD mod this year, somehow it'll appear but then I won't need a 128GB SSD when I have a 1TB SSD. Thanks.

 

[PedroTango]

Hi, I have the same iMac Late 2015 27" 5K with 2TB fusion on Catalina V10.15.7, and symptoms but primarily it just runs really slow. Internal drive speed was 400/1600(W/R) now 100/100 or often 50/50 . SSD is shown as AHCI in system report. External HDD WD 4TB Red Plus on usb 3.0 runs 170/170. No errors, Repair shows OK. Disk Utility shows system value (11.9GB used) and Data volume on SATA HDD but SSD does not appear in Disk Utility (only ST2000DM001) and disk utility device size is 2.0 TB not 2.128TB. It appears to not use the SSD perhaps? Any thoughts/suggestions ?

 

[stealthytolkien]

Hi, I have the same iMac Late 2015 27" 5K with 2TB fusion on Catalina V10.15.7, and symptoms but primarily it just runs really slow. Internal drive speed was 400/1600(W/R) now 100/100 or often 50/50 . SSD is shown as AHCI in system report. External HDD WD 4TB Red Plus on usb 3.0 runs 170/170. No errors, Repair shows OK. Disk Utility shows system value (11.9GB used) and Data volume on SATA HDD but SSD does not appear in Disk Utility (only ST2000DM001) and disk utility device size is 2.0 TB not 2.128TB. It appears to not use the SSD perhaps? Any thoughts/suggestions ?View attachment 2004384

Same problem here. Any solution?

 

[jeannius]

I've just run into this issue with the original SSD failing and it gets even more complicated if you are trying to run Monterey! No matter how I go about it, if I install Monterey, the dead SSD seems to be causing the OS, with the exception of system profiler, not to see or access any other drives, aside from my network NAS! Everything is turned on to show drives, but they don't show on the desktop, sidebar, disk utility, startup disk or 3rd party repair programs such as disk drill. I downgraded to Big Sur, and all is fine...

I read in some other forum that it may be related to the Monterey OS being designed to be used on a fusion drive with this Mac...but am still researching the problem... so, at this point, I may be stuck using Big Sur unless I want to jury rig the open core thing to force an unsupported system. Like you all, it's a late 2015 27 inch with Apple SSD saying 'unknown'...same interface.

The really weird thing is that no matter which source for Monterey I boot with, be it internal drive, external drive, bootable flash, or recovery, the only thing it sees is what it booted on! so if I boot with recovery, it only shows the recovery temp partition in disk util....not the internal, externals or flash drives!
so frustrated! you can see in the image that everything is checked off to show the drives but only the boot and potentially. network show up.