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.

 

[Significant1]

I know it is an old thread, but I had the same problem with a newly acquired iMac Pro. Tried making a fresh install, in case it was due to something from backup. Also, none of the settings changes made a difference.

Then it hit. I had forgotten one of the golden rules, when trying to solve a problem. Disconnect everything and try to isolate the problem. Turned out my Lenovo thunderbolt dock was causing it (at least when it was not itself connected to power). With the iMac Pro, I only rally need the HDMI port, so I have now ordered a USB to HDMI cable instead.