iMac Overheating

Hi Guys, not sure if this the right procedure, but I have an issue to report. Lately my iMac (Retina 5K, 27-inch, Late 2014, 4 GHz Intel Core i7, 32 GB 1600 MHz DDR3, Radeon R9 M295X 4096 MB) starts to overheat the GPU (>100 deg C) and fan goes to max speed (very noisy, hence the problem). Only happens on the album screen (Tracks), stops when I switch to Credits screen, minimise Roon, or go back to main menu. Is there some setting I should change, is Roon running something in the background and should I just wait for it to complete (eg indexing), or this is a bug? I’m running ver 1.2 (build 165) and my OSX is 10.12.1.

Hi @Roel_Haitjema ---- Thank you for the the feedback. This is not something I have come across before and would like to get a copy of your logs to be analyzed by our developers so they can determine what may be going on here. I will be contacting momentarily via PM with instructions


I have the same iMac and it heats up all the time and that was before Roon. Mine was not sensitive to Roon, but when many Safari windows are open or lots of photo processing is being done, it really gets hot. When a virus scan is done it smokes! I consider it an Apple iMac bug that I just deal with using TG Pro to control the fan. Seems to be display driven processing mainly. I moved Roon core off onto a SonicTransporter so I can shut the iMac down in the music room.

Hi guys,

I may have worked it out. I had two DACs connected via USB to my iMac (NAD M51 and Cambridge Audio DacMagic via a Musical Fidelity V-Link II asynchronous USB to SPDIF convertor). I had linked them in Roon to
do AB tests to see which one I liked best. I chose the M51 and physically disconnected the DacMagic/V-Link II setup. The DacMagic/V-link setup no longer showed up as an audio device under the setup tab, but the two linked devices still showed as the chosen output zone when playing music.

I broke the link between the two DACs and now the temperatures are staying in the normal zone. The fact that the GPU ran hot was probably a red herring, with something else on the logic board in the vicinity (USB related?) running flat-out looking for the disconnected V-link/DacMagic. It just took me a while to realise the high temp issue started after I had disconnected the second DAC.

Hope I haven’t wasted everyone’s time.

Thanks and regards,

1 Like

Hi @Roel_Haitjema ----- Thank you for the follow up and sharing your observation(s) with me. Please keep me updated if anything else comes up and I will gladly lend a hand :sunglasses: Happy listening!



I have an iMac 27” 2011 running windows 7 under Bootcamp. Running Roon would boost the GPU Diode temp to 99 degrees!
Use the standard Windows Desktop in screen preferences
Minimize Roon when playing (the temp drops right away)