I have a 2017 27" iMac with a 4.2 GHz Intel Core i7. It's been having some issues lately where every now and then the entire system will gradually freeze, forcing me to hard reboot the computer. So to see if there's a hardware issue, I started running prime95 in stress test mode to see if any errors were detected.
After running for about 20 minutes, I checked the core temperature readings for my CPU and they were all hovering around 95 C. Ordinarily I'd think that's way too hot but with the design of the iMac I'm not sure. I stopped prime95 and after my system was idle for a little while the core temperatures are now hovering around 60 C.
Is that temperature too hot, or is this normal for an iMac?
edit: After the system was idling all night the temperature went down to 45 C, which is of course a good idle temperature. So no worries there.
edit 2: After doing more research I've discovered this is a widespread issue with the Intel Core i7-7700k, and affects all iMacs that have it. Apparently Intel claims its temperature spiking to 90 C during normal use and hitting 100 C during heavy use is normal. Seems wrong to me, but who am I to argue with Intel?