Corsair H100i V2 unusually warm...

[darthpepe]

Hey there, everybody.
Yesterday I bought and received (free same day shipping from amazon prime, YEET) a Corsair H100i v2 240mm AIO Liquid Cooling System. This was an upgrade from my previous AIO, the Corsair H55 120mm. HOWEVER, the temps have remained nearly the exact same... I have seen people using the same cooler in the same case as me (NZXT S340) getting idle temps of low 20s and max load of 50-60c, while my idle temps seem to be jumping back and forth from 30c all the way up to nearly 40c... Under load I saw the temps get nearly all the way up to 90c, which terrified me. But under load I would see them drop to even 65c! What??!! That kind of difference does NOT bode well. Those temps are pretty much the same as I was getting with my 120mm rad. I'm so confused as to why the temps jump back and forth nearly 10 degrees at idle and under load (and this is monitored through HWMonitor, by the way).

I'm so lost... Please send help

CPU: 5820k clocked at 4.3GHz @ 1.25v
Radiator is mounted at the front of the case with fans as intake exactly how the manual told me to mount them.

 

[8924th]

Water is much less efficient at transferring heat than metal, so it's also much more difficult to stabilize its temperature. Seeing spikes come and go shouldn't be so much of a surprise quite honestly. How hot your CPU gets also depends on the kind of workload it is under, and OCCT can be a good example of that. A personal example:

Large data set: 100% use = 73C
Small data set: 100% use = 82C

You also have to consider the setup of the person who you're currently using as the comparison point for your own temperatures. Getting idle temps at low 20s may not mean much if the CPU is delided and the ambient room temp is 15C. This is likely information you don't have access to at the time. A CPU can't have a lower temperature than the ambient temperature so if your room is warm, don't expect the water running through the loop being any colder

To be seeing jumps in temperatures like that shouldn't be too worrying. The sensor's on the die itself and not reading the water temperature so you can expect it to be much more accurate of sudden changes like that. The real issue would be if you're seeing consistent temperatures averaging on the 90s mark for extended periods of time. Your CPU would be blowing off steam in that case.. quite literally.

 

[gigabyte2020]

Well as 8924th said, liquid cooling depends mostly on the room temp. (Ambient) for example: Iam in Alexandria, Egypt and I have cooler master seidon 120V plus liquid cpu cooler, however in winter season my cpu temp goes from 17-21 but in summer season it starts from 31-35 deg. Celsius even though in desktop and my cpu is not oced running at 1.2375v and my pump is running at FULL speed so ur radiator won't be less than ur room temp. Another solution which might help is try to inc. the speed of ur pump if it's not in max. Speed it might makes some difference since it will inc. the water circulation and dissipates heat MORE effectively but be careful not to fry ur pump, but if we are talking about 90 deg. Celsius then i think u need to downclock ur cpu a little bec. The water in the radiator is almost going vapour (steam) like 8924th said

 

[darthpepe]

So, I reapplied thermal paste. The highest temp I've seen on a core while running Prime95 is 88c, however it backed down substantially from there. Right now temps are fluctuating between high 60s and high 70s, some reaching into 80s territory. I will admit the room is pretty warm, and I will do some more testing at night when it gets colder.

 

[8924th]

So long as your temperatures are squaring off to a stable point, that's great. Still a bit on the toasty side with 80C considering its water, so you may want to either up the pump/fan speeds or lower the clock a little.

Ultimately your best benchmark would be to run a gaming marathon since it's still Sunday and keep an eye on the temperatures and stability while you're at it

 

[darthpepe]

So long as your temperatures are squaring off to a stable point, that's great. Still a bit on the toasty side with 80C considering its water, so you may want to either up the pump/fan speeds or lower the clock a little.

Ultimately your best benchmark would be to run a gaming marathon since it's still Sunday and keep an eye on the temperatures and stability while you're at it

During gaming I never really see the CPU get past 50-55c. It's just when I run these synthetic test that stress at 100%. The temps get to 88c occasionally. They do fluctuate a lot under load, however. Sometimes they'll drop all the way down to 60c then come back up after 5 minutes to upper 70s occasionally low 80s.