AIO is doing weird stuff

mayham776 · January 18, 2022

now I've been having CPU heating problems with my corsair h100i GTX. I would get like 60c in bios now I know this might sound stupid but here me out, when its getting 60c in bios or just in chrome doing nothing I unplug the header to power the CPU block and fan and plug it back on (with the system running ) but when i plug it back in the same place the CPU_Fan header i end up going from 60c to 38-40c super low temps but than over time it heats up again to 60c but holds 38-40c for a decent amount of time. is it a bad cable or bad pump bad CPU fan header?

Bombastinator · January 18, 2022

1 hour ago, mayham776 said:

now I've been having CPU heating problems with my corsair h100i GTX. I would get like 60c in bios now I know this might sound stupid but here me out, when its getting 60c in bios or just in chrome doing nothing I unplug the header to power the CPU block and fan and plug it back on (with the system running ) but when i plug it back in the same place the CPU_Fan header i end up going from 60c to 38-40c super low temps but than over time it heats up again to 60c but holds 38-40c for a decent amount of time. is it a bad cable or bad pump bad CPU fan header?

That’s… not normal. The cpu fan doesn’t detect cpu temp at all. It is controlled by cpu temp though. If everything is working right it would mean that the cpu fan increases your temps by 20c which strikes me as unlikely. I don’t know where you’re plugging it into so I’m not sure what “header” means in this instance, but something is badly messed up. Probably software wise, though the quite narrow possibility that your fan merely actually does a lot more harm than good remains undisproven.

For Science! · January 18, 2022

1 hour ago, mayham776 said:

now I've been having CPU heating problems with my corsair h100i GTX. I would get like 60c in bios now I know this might sound stupid but here me out, when its getting 60c in bios or just in chrome doing nothing I unplug the header to power the CPU block and fan and plug it back on (with the system running ) but when i plug it back in the same place the CPU_Fan header i end up going from 60c to 38-40c super low temps but than over time it heats up again to 60c but holds 38-40c for a decent amount of time. is it a bad cable or bad pump bad CPU fan header?

Quick guess would be that you have a fan curve set on the CPU_Fan header. AIO pumps in theory should operate at a constant 12 V, as the pump speed should not be changed with temperature - you want a constant flow of coolant at all times regardless of CPU temperature.

In a nutshell I guess this is what is happening.

CPU starts up (lets say 25 degrees) and so your BIOS sends less than 12 V to the pump, so it either is very slow or off.

Since there is too little flow, the coolant in the CPU block gradually heats up (to lets say 45 degrees) and subsequently the CPU heats up too (eg 70 degrees).

At this point the BIOS is at a high enough place of the fan curve to send sufficient voltage to the pump and the cooler actually starts pumping

So you end up at a place where the pump is only partially powered but only if the temp of the CPU is high, so you idle at around 60.

If you unplug the cooler entirely during operation, presumably the CPU will heat up even more (lets say the 80's). Then the BIOS is at the 12 V range for the cooler.

So when you re-plug the cooler in, it operates as intended for a while, completely changing the coolant within the CPU block, (and then stops, because the CPU is cold again)

And because the pump stops, the coolant gradually heats up again with no flow.