iMac Pro Power issues
I have an iMac Pro 10 core -- using OWC raids and SoftRAID beta -- Big Sur. Not sure if anyone else has seen this issue, but the iMac has started getting a power issue; It shuts down if the heat, or processors get too hot. I have a BU battery/Surge protector and when it loses power, it beeps. Often when playing video or exporting video I'll get the "beep" of power loss -- it is intermittent. Thinking it was a hardware issue, I brought it back to Apple and they did tests on it and couldn't find any hardware issues. They wiped the drive and reinstalled Big Sur from scratch. I restored from time machine and reinstalled the Beta software. So far so good -- except for a startup beep (lose of power) when I booted up this morning.
Just reporting what's happening, in case anyone else has had this issue.
this is an old thread, but talks about beeps being RAM issues.
Most people do not know this, but Crucial and Apple RAM do not mix, they are the same manufacturer, but Apples customer modifications make them somewhat incompatible.
Another idea is increasing fan speed on warmer days:
I assume Apple checked the vents underneath for dust? I would take it outside, reverse the air on your best vacuum and blow as much dust as you can from it. (iMac's are hard to take apart, so its not practical to take it apart to clean the dust out.)
give those a try. I guess you can also monitor CPU temperature (istat menus for example, but disable its SMART tests, the app tests it hourly which is bad.)
All RAM was installed factory by Apple -- so it's not a Crucial RAM instal. Also not dusty computer -- Apple did a full test and could not reproduce the issue. I ran into the problem to day running Render Garden for After Effects using multicore for rendering -- rendering to OWC drive. Still not sure if it's a SoftRAID/BIG SUR issue.
Impossible for it to be a SoftRAID issue. Big Sur could up the heat possibly. You need to be able to reproduce it to get Apple to pay attention. Certainly seems like a hardware (heat) issue to me.
2nd Test. I collected the project and rendered using Render Garden to the desktop -- so all elements and footage was bypassing the OWC THUNDERBOLT 3, SoftRAID path. The results were a clean render and no loss of power. This was done earlier will rendering TO THE OWC THUNDERBOLT 3/SOFTRAID path and it caused a power loss.
Could be the OWC Raid?
Still cannot be a SoftRAID caused problem. Try making your Thunderbay an Apple RAID 0 problem.
Perhaps the extra disk throughput is generating more CPU heat. Perhaps a Thunderbolt issue.
SoftRAID's driver is just a pass through driver, all IO is performed by the OS (disktool).
You may have a clue to the trigger (heat generated by rendering to the fast volume, perhaps), but correlation is not causation.
Keep working on figuring this out. I cannot guess if this could be an enclosure issue, I think in the realm of possibility, but seems unlikely.
Problem solved -- had nothing to do with Mac or SoftRaid -- the iMac was overpowering Backup Battery/Surge protector. Thanks for you indulgence as I tracked down this issue.