CPU extreme temps during first boot

[Andrea Franchini]

hi everyone.

Its been a while since when I start up my computer for the first time of the day the cpu temp quickly jumps to around 85-90 c. The system works correctly, windows boots without issues, cpu usage is near nothing, and after a while, 2 or 3 minutes the temp suddenly go back to 25 c. If i turn off the system and turn on again the problem doesnt show up, same with reboot. if i stress test the system temps are really good. these extreme temp moments keep happening even in the bios after a reboot, its just a matter of time before everything go back to normal.

Im really getting crazy, because as far as I remember the pc used to work perfectly before (havent use it for a while), and now its been 3 months with this weird behavior.

specs:
intel 3960x
asus deluxe x79
cooler ekwb predator 360 v1.1 connected to cpu fan as required by the manual
windows 10
bios latest updates ...

Is it a sensor issue, is it the pump but then why would it work after the first boot of the day, ...?

edit
cpu and gpu 980 ti are connected to the ekwb predator 360 v1.1. while cpu at first start up is sky high, gpu temp are around room temp as with motherboard. today ill start the system and touch the tubes. if ill feel water flowing but still high temp, then without a doubt it should be a sensor reading error, if no water flows then ...

 

[fidelio]

definitely sounds like an issue with liquid cooling and the radiator with the computer starting up fine then quickly overheating. Try replacing the liquid cooling with a normal heat-sink and fan combo to see if the problem dissipates.

 

[Andrea Franchini]

definitely sounds like an issue with liquid cooling and the radiator with the computer starting up fine then quickly overheating. Try replacing the liquid cooling with a normal heat-sink and fan combo to see if the problem dissipates.

Yeah, but you know, could you elaborate a little bit on your answer? At least try to justify the hours and money I should invest to find a x79 cooler?

Thanks

 

[Andrea Franchini]

Today I tried to turn on the system to find whether the water is actually flowing or not. Of course the system didn't show any of the before mentioned problems, and started smoothly and cold as it should always do. As far as I could tell the water was defenetly flowing at least from one tube where there were some vibration (hence by logic it also flowing in the other direction). Today's behavior was unexpected since it was a while since I had a first start without problem, but the only thing I did was unplug the ethernet cable, an optical cable, hdmi cable and slightly move the pc forward to open the left panel. Ill try again later to see if I can replicate again the problem.

I also would like to add that the 3 radiator fans and the pump are connected to a hub, then a single cable is connected to CPU_FAN on the motherboard. Despite the 4 pin on the motherboard connector, the hub cable has only 2 pin. I was also wondering if sometimes the pump doesn't receive enough power to start, then after a while it kicks in and normalize the temperature.

 

[Andrea Franchini]

Today after multiple test, I wasnt able to reproduce any of the problems. So I decided move the pump 4 pin connector from the central hub, which offered a single pwm signal for both fans and pump (horrible idea EKWB!), to CPU_OPT on my motherboard. Despite being another pwm connector Ill simply set it to always run at full speed (which is preferable for a pump), while the CPU_FAN will handle just the radiators fans. At this point if the problem should reappear I can conclude a thermal read problem from the cpu, otherwise the pump is the culprit, hence EKWB will hear me loud and clear because this would be the third time I have to change this predator AIO.