Question CPU Fan speed constantly spiking on idle

[pinocammino]

Hello people, new user here.
I just upgraded some pc components (Full PC specs in the end) and, while running some tests with OCCT to be sure that everything was working correctly, i noticed that, while the pc is idling, the CPU fan rpm keeps spiking every 1-2 seconds from 0 to 1200-1400 and back (screenshot attached) while every other case fan value remains static (like 20 rpm variance) the whole time. The fans are physically spinning the whole time, no variations in speed noticeable but ofc being the spikes at 1 seconds interval, momentum is also a factor and i think there isn't enough time to actually slow down.
During loads or stress tests the CPU fan behaviour seems what's to be expected, going up, the higher the CPU temp is and never spiking (second attached screenshot. Test is only 1 minute long just for screenshot purpose but i've been running longer ones with different loads and in all of them the fan behaviour seemed coherent to what should be expected and the temperature too seemed to stay in expected parameters).
This leads to my question, is this a normal behaviour for the cpu fan that i somehow always ignored (or changed in the last 6 years since last time i changed pc) or there is something weird going on?

FULL PC SPECS
CPU intel i7 14700k
MOTHERBOARD MSI z790 gaming plus wifi
GPU pny 3070 8gb
RAM corsair vengeance gddr5 6000 2x16
AIO MSI MAG coreliquid m240
SSD crucial P3 plus
PSU MSI 850w 80+

Case has 1 120mm rear fan and 3 120mm front fans

ATTACHMENTS

https://imgur.com/a/usC24N0

View: https://imgur.com/a/usC24N0
Idle monitoring

https://imgur.com/a/ARmVoKE

View: https://imgur.com/a/ARmVoKE
Stress test

 

[Lutfij]

Welcome to the forums, newcomer!

I just upgraded some pc components
What were you working with prior if the above listed specs are of your system post-upgrade?

Case has 1 120mm rear fan and 3 120mm front fans
You forgot to mention the make and model of your case. Fans came bundled with the case or did you go for aftermarket options?

 

[pinocammino]

Thank you.
Forgive me but i won't be able to be as exhaustive as for the new spec cause i don't remember all the old components by heart and don't have them with me atm to check.

What were you working with prior if the above listed specs are of your system post-upgrade?
CPU intel i7 8700
MOBO MSI gaming pro carbon B360
GPU 3070 (this has been changed midway so stayed the same in new configuration waiting for serie 50xx)
RAM 2x8 corsair vengeance ddr4
AIO arctic liquid freezer 240 (not 100% sure on this one sorry but reasonably so)
SSD can't remember sorry, just that it was 512 gb and not the nvme version
CORSAIR RM 750w 80+
1 rear fan included with case (can't remember model)
2 front fan added in front (can't remember anything about those)
CASE again can't remember

You forgot to mention the make and model of your case. Fans came bundled with the case or did you go for aftermarket options?
You're right sorry.
Case is a MSI vampiric 010x. The rear fan is the case specific one. The 3 front ones i ordered them separately but, maybe in a not that smart way, i didn't specify anything to my retailer other than them to be 120mm so that they could fit the case, and i didn't really bother to check for model later. If it's really that important to know them (considering the cpu fan readings showing that behaviour belongs to the AIO) i guess i could check in the case if i can find the model without having to dismantle too much, otherwise i can phone my retailer and ask but that has to wait till monday.

Oh i forgot to mention that BIOS and motherboard firmware are both updated to the latest version (oct 9th 2024) same goes for driver and even Windows