My beloved late 2015 27" iMac's Fusion drive died (I think the built in SSD died – Disk Utility refuses to format it saying it can't write to the last block).
I decided to swap out the internal 3TB spinning HDD with a 4TB SSD: I got the Samsung 860 QVO 4 TB drive. After migrating a CCC backup, it boots up and runs fine but I had some random restarts. I then decided to format and fresh install MacOS Mojave from internet recovery. The SSD is connected via the internal SATA cable, using an OWC adapter for the temp sensor. I did note a reboot when the SSD was initally installed using a Thnderbolt 2 enclosure (LaCie 2big) as well but didn't grab the kernel panic report.
With the SSD mounted internally, and a fresh from internet install of Catalina, I'm still getting sudden shutdown and reboot, especially during Migration Assistant. I get the following log after booting into MacOS Catalina.
Basically it's AppleAHCIDiskQueueManager::setPowerState timed out
I'm sure it's the QVO drive itself – I read some reviews that noted they had trouble detecting the drive transiently on booting on a PC mother board. I suspect it's somehow dropping of the SATA connection and then causing the KP above but not sure if anyone has other suggestions for a fix?
There aren't any other 4TB SSDs in this price range (I had a 3TB Fusion drive before) and I don't want to spend the amount to go to a EVO drive which is double the price at this storage tier. I might just do a 2TB SSD but I'd have to move stuff externally.