2017 iMac 27", booting from external SSD - freezing/crashing when performing certain tasks

[Hermolicious84]

I have a 2017 27" iMac with an internal 1TB Fusion Drive, and I am booting MacOS from a 1TB NVME drive in an external USB-C (3.1) enclosure. The external SSD has BlackMagic speeds of ~750 read/write consistently. The internal Fusion drive is formatted and used for extra storage.

During certain tasks -- which seem to be more processor or USB-bandwidth intensive -- I am getting beachball freezes which inevitably lead to a crash with the black screen message "Your computer restarted because of a problem" (or whatever it is). I do not do a ton of CPU intensive tasks in general. I don't play games or do heavy image or video editing.

My primary trigger is converting video files to be compatible with my Xbox and other devices for playback. Usually, I'm just doing passthrough of the video portion and converting the audio to a compatible codec and repackaging in a .mkv file. The files are being read from the external boot SSD and then being written to either another external USB drive or the internal Fusion Drive. It is not 100% consistent. I can perform the task on a file and cause a crash, and then reboot and perform the same conversion on the same file again and it will work just fine.

Any idea what could be causing this problem, what I could do about it?

 

[SiII5mb]

I've never had any joy booting a mac from an external drive since the end of scsi and every Mac OS I've used has always had atrocious USB connectivity causing exactly the problems you describe. They spend most of their time falling asleep and caching their memoirs to be bothered doing my bidding when I've needed them to. Sorry I'm not much help

 

[Hermolicious84]

I've never had any joy booting a mac from an external drive since the end of scsi and every Mac OS I've used has always had atrocious USB connectivity causing exactly the problems you describe. They spend most of their time falling asleep and caching their memoirs to be bothered doing my bidding when I've needed them to. Sorry I'm not much help

That's okay. I also had the initial problem of the drive being put to sleep and then needing a restart every time I tried to wake it... I solved that by unchecking "Put hard disks to sleep when possible" in the energy saver settings, and also using the app Amphetamine's "Drive Alive" feature to access the drive once every couple minutes.

I felt pretty good about not having those big issues anymore, but this new one is definitely annoying enough to be concerning.

 

[faizalqurni]

I also have the same issue using Samsung T5 SSD on my 2015 27" iMac. The system keeps crashing randomly, mostly when I'm using software like Photoshop, Ilustrator, or GPU-activity related app.

Do you managed to solve this issue, Hermolicious?