iMac Pro iMAC Pro gets warm when in sleep mode!??

[randomkaos]

Well, Apple sent me a new iMac Pro. Slowly installed some of my software back on over a period of two weeks. I also replace both backup drives to SSD's, new Arris cable modem, new Netgear router, and new speakers. After 4 weeks of use overheating is back. Did a clean installation with only Apple software and still there. Unplugged my Cat 5 and it sleeps like a baby. Ordered a usb3 to Cat 5 and will see if that does it and i will post my result after a couple days of testing. Also, I monitor the heat on each CPU and quit a few other items using iStats.

Stay Tuned....

 

[Peter_M]

Disconnecting the enclosure and rebooting doesn't seem to fix mine.

I'm also finding now that my external drives are not powering down when the iMac sleeps. I may have to try disconnecting everything and reseting things like pram....

Update: Dunno if relevant, the only way this one will stay cool when sleeping is with all the external devices disconnected. When there is a drive(s) connected, it seems to spin it/them up every 30 seconds or so. Power saver is set to spin down disks.

The external HD spin up issue during sleep is a problem with all iMacs and MacBooks, and have been for many years. For some reason Apple can’t or won’t fix it.

 

[ColdCase]

I hadn't noticed my older iMac and macbook spinning up drives when sleeping, but I wouldn't be surprised many others have seen it. The macbooks, during some weeks, will wake an external monitor from time to time, other weeks not.

 

[randomkaos]

Well after a week of testing the USB-3 to Cat5 I can safely say this is an issue with the iMac Pro connecting thru the built in network connection. rraven is correct in the earlier post. I have no idea whether this is hardware or software but the dongle I used allows the computer to sleep with factory defaults in the energy savings in Sys Preferences. I opted for the Anker adapter.
Another strange thing I noticed is my network connection is faster, as per Speedtest.

Good Luck All!

 

[CasablancaDR]

Well, I just realized that my base model iMac Pro was doing the same thing.

I could hear from several weeks a little flow of fan spinning, nothing fancy but more noticeable than usually. And the iMac was quite hot, even at rest.

Tried everything : SMC, NVRAM, unplugging my RAID array or my ethernet cable. Nothing's changed. The temp IDLE was around 53°c, which was almost 10°c + hotter than usual.

A clean install with the last Mojave update did the trick in my case and the iMac does perform well now. But what the heck happened ?

 

[randomkaos]

I wish you luck. I did 2 clean installs and ended back with the heat problem.
The only thing that has worked is the little Amazon usb3 to cat5 adapter. Every time I use the Pro's network connection,... HOT,HOT,HOT!

 

[Joannes Spriet]

To All,
I had the same problem.
I could solve doing following:
In Energy saver: Turn display off after: Never
After bringing iMac in Sleep mode switch off the monitor.
Then: iMac becomes or stays perfectly cold.
However must be a software problem about communication iMac - Monitor.
Joannes
PS: before going in sleep mode I also switch off the WiFi and Ethernet communication, but this mainly for security reasons.