Over the past few months I installed macOS for 4 people on an external SSD.

This week I decided to also upgrade my "Fusion Drive" to an external SSD, because it just sucks.

For me I chose a Samsung T7 1TB. I hooked it up via USB A.

In the past 2-3 days my Mac crashed multiple times. First spinning ball of death, then full crash and the message "Your computer restarted because of a problem".

Before writing this I switched to USB C, maybe it's a power problem for the drive.

The SSD has a small LED that blinks when something uses the SSD. Right when the crash happens this light stays on and stops blinking.

All others with an external SSD don't have this problem. But to be fair, I'm the only "power user" of the 5 people (including me) that really uses some resources of the mac and not only Word, Mail and Chrome (like the others do).

So is an external boot SSD not made for high bandwidth loads? Or what else could be the problem here?


  • iMac 2019
  • macOS 12.5

Update: A few minutes ago it crashed again, while I wasn't even doing anything. I saw it from a distance that it just restarted.

Crash log from last crash:

panic(cpu 1 caller 0xffffff801cb1cd76):  initproc exited -- exit reason namespace 2 subcode 0xa description: none

uuid info:
 0x10d7f9000    uuid = <58a27827-c685-3a36-8cb2-64c3f18dad6b>
 0x112307000    uuid = <f71fb3ca-5fcc-3577-9457-b047888a46d1>

Thread 1 crashed

RAX: 0x00007000092e22e8, RBX: 0x000000010d861100, RCX: 0x0000000000000000, RDX: 0x000000010002d284
RSP: 0x00007000092e2240, RBP: 0x00007000092e2350, RSI: 0x000000010d861120, RDI: 0x000000010d861110
R8:  0x000000010d7f9b30, R9:  0x0000000000000e40, R10: 0x00000000000004a8, R11: 0x00000000000001ff
R12: 0x000000010002d284, R13: 0x000000010d7f9000, R14: 0x000000010d85d000, R15: 0x00007000092e2418
RFL: 0x0000000000010246, RIP: 0x000000011233bd66, CS:  0x000000000000002b, SS:  0x0000000000000023

Thread 0: 0xffffff86c57fb000

Thread 1: 0xffffff86d1121540

Thread 2: 0xffffff86c882daa0

Thread 3: 0xffffff86d2419540

Thread 4: 0xffffff86cbb02540

Mac OS version:

Kernel version:
Darwin Kernel Version 21.6.0: Sat Jun 18 17:07:25 PDT 2022; root:xnu-8020.140.41~1/RELEASE_X86_64
Kernel UUID: E3E2BC4D-7B6F-39CC-8890-73A6FB513830
System model name: iMac19,1 (Mac-AA95B1DDAB278B95)
System shutdown begun: NO
Panic diags file available: NO (0xe00002bc)

One thing to add:
All other boot drives I‘ve set up were a fresh install with new OS and files copied manual.

With my mac I did a full Time Machine backup with all files and then restored that Time Machine backup to the SSD.
Could this be the problem?

I also have some other weird issues, but I thought they are caching problems:

  • My reminders app is completely broken
  • My login image is gone, it‘s a grey silhouette of a person, in the system settings I can‘t change it because the menu is broken

Did a first aid check of the drive and the boot container, no results, everything fine according to the test.

  • If one Mac is having kernel panics when running from an OS/drive that works fine on other Macs, then I'd suggest the problem is not the drive, but likely to be a hardware issue.
    – benwiggy
    Commented Aug 12, 2022 at 10:09
  • Well, I didn't test one of the other boot drives on my mac. They don't have issues with their mac with their ssd in combination. Never swapped them around for testing.
    – jona
    Commented Aug 12, 2022 at 10:16

1 Answer 1


Thanks @jona for posting this. It's 2024 now and we've been having this exact problem for about a year on 3 very similar iMacs (2017, 2019, 2020). Tried 4 SSD brands (WD, Crucual, Samsung, SP), many cables (SATA to USB-C, SATA to USB 3), regular form factor SSDs and M.2 too. I'm suspecting the problem started with Ventura because we've been using external SSDs to boot our iMacs for more than 10 years without any issue. Also noticed that Bluetooth tends to disconnect a few minutes or sometimes hours before a crash. Of course all installs were clean and we ran some tests without anything else connected to the iMac except for keyboad, mouse and boot SSD. Sometimes it would crash during the night, but most of the time it's in the middle of something important of course ;).

Fusion Drives are far from the best and they're the reason we use external SSDs. Before Intel "super thin" iMacs, we replaced internal 5.25' drives with SSDs but since the upgrade process was made tedious, we used extrnal -- once again without any issue for years.

We're well aware that the recent iMac and Mac Studio (and every Mac but the Pro) are totally non-upgradeable, so we'd like to hold onto our iMacs for as long as we can.

Not helpful I know, just wanted to add our voice.


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