I'm not looking for any fix for this, but I thought it worth mentioning in case anyone else experiences the same thing…
Since H17, I've been experiencing complete system crashes on my iMac Pro when working in Houdini… It will happen if or when I do something (often by mistake) possibly memory or geometry heavy, an intensive task that you might expect would crash an application. It's usually something done by accident, like creating too much geometry, but it has also happened when doing fairly innocuous things. Whatever the cause, for the entire system to cut-out to black screen is highly unusual… The beachball will start spinning, then around 10 seconds later the Mac will just cut out to black screen and switch off…
I just wanted to mention it in case anyone else has experienced the same thing. At the moment I don't know whether it's limited to this model of Mac in particular or whether H17 is actually to blame in any way, shape or form… All I can say is that it's only started happening very recently, and it's only ever happened when I've been working in H17.
… and just on a side note completely unrelated to Houdini… I've also noticed glitches with the sound on this iMac Pro, it's like someone tapping a live microphone … Some people have attributed this to the T2 chip, whatever that is… I only mention it because it's something that, although happens every now and then, will always happen just before the system cuts out as mentioned above …