Question 4790K - Recent increase in temps


May 29, 2012
Build a 4790K system run in an Asus z97 pro wifi ac cooled Corsair H100i cooler with washer mod around 4 years ago. At the time just did basic OC testing, and bumped the boost clock speeds from 4.4 to 4.6GHz. I don't have the original thermal data but the system was stable under load.

Over the last couple of months temperatures have deteriorated with the CPU reaching thermal throttling and getting system freezes (coretemp + Corsair iCue giving temps 90 - 100C) under a medium load. Idle temperatures were sitting high 40's. It is currently winter in AUS and ambient temps would be low 20'sC in the room when the PC is operating.

I tried reseating the cpu cooler with AS5 with no luck and have currently swapped to a intel stock cooler to compare. Both heat sinks are dust free. Corsair 450D.

I noted the CPU seemed to be running at boost with little load and wondered if there was a software issue so turned boost off in BIOS to see how it performed under load at stock. Prime95 couldn't maintain load at 4GHz, throttling back to 3.9GHz at 100C.

So far I have had little time to troubleshoot property and I am looking for suggestions in troubleshooting, any links to similar issues I may have missed in my search. Many of the posts I have found regarding the 4790K running hot lead to delidding articles, which could be on the table if I can't resolve in another way.

At this stage I suspect the H100i loosened over time causing the CPU to run hot for a longer, unmonitored period. I hope I am terrible at applying thermal paste/tension from the CPU to the cooler is too low and providing poor heat transfer and there is an easy resolution. I fear this may have affected the TIM between the die and the heat spreader.

My current list of to dos:
  • Confirm the seating of the stock cooler (time restraints meant attaching wasn't my best work)
  • Confirm expected exhaust temperatures (air from intel, cooling loop on h100i seemed cooler than I would expect for a 100C CPU)
  • Save some testing to post here for reference
  • Continue research and follow advice from here
Thank you for any and all help.


Over time the TIM can get bad. In your case, I would delid the CPU and replace the TIM of the die and heat spreader.

Some things you can try before delidding:
update the BIOS
reset the BIOS by jumper
reinstall/update all drivers