As a first time Mac Rumor user I have installed Open Core 0.7.8 on a cMP 5,1 with 2 - 3.46 processors 128 GB of Ram, 4 2TB drives in the 4 bays and a Sonnet Nvme card with 2 2TB Samsung EV 970 SSD drives, Sapphire Pulse RX580 8gb and at present I am running High Sierra with the hope I an soon update to Big Sur. I am booting off of the SSD and am pleased with the speed bump up, the boot picker and screen and all drives as Internal ones. However, before i do update I would like to find out why after about an hour of not using the computer it goes in to a sleep situation which I can't get it to wake up fully. When I try to wake it up, the sleep screens go out, the desktop is then on view and after a couple of seconds everything freezes. The only way to proceed is to force the cMP to shutdown. Then I restart and all seems well. I would greatly appreciate any help in figuring out what is going on with this sleep mode. My Energy settings are set for no sleep for monitors or drives.