I received my iMac Pro all extras (18 cores, 128 GB RAM, 4 TB and Vega 64) and installed it on Monday. While working on my previous machine (a 2010 Mac Pro), the machine launched its screensaver and then went to sleep (as expected). Suddenly, the fans started to run full speed. The machine was unresponsive to keyboard or mouse. I did a hard restart (pressing the on-off button until the machine turned off). The machine never restarted. I don't even see the Apple logo on the boot screen. When I press the on-off button, I hear a whisper inside the Mac and nothing more. Every now and then, the same procedure gets the fans running full speed again. I tried to boot in target disk mode but nothing happens. I conclude that the most powerful Mac ever seems to still be underpowered to run a screensaver without dying. And that 2000 USD per hour which are valid only for the first 6 hours of use does not look like a too bad business model. Has anyone experienced a similar issue with an iMac Pro 18C?