imac keeps crashing, rebooting?

[Randy B. Singer]

If you suspect that your hard drive is failing, I recommend that you run:

Apple Diagnostics
How to use Apple Diagnostics on your Mac - Apple Support

You might also try this excellent product, but I don't know if it is compatible with an APFS drives:

DriveDX - free demo
DriveDx - the most advanced drive health diagnostics and monitoring utility

 

[chscag]

You might also try this excellent product, but I don't know if it is compatible with an APFS drives:

DriveDX - free demo
DriveDx - the most advanced drive health diagnostics and monitoring utility

It is compatible. I have the latest version and I use it to check my Apple SSD on my iMac which runs Catalina.

 

[macgig]

I ran DriveDX... it says the drive is ok. guess I'll keep and eye on it and keep good backups. lol

OS is the same on both drives... have to wonder if the power supply is slowly dying? I'll just keep an eye on it for now.