linttRa

asROCK x570 gaming phantom 4. On this MOBO fan on SB is also very noisy but not as audiable as peaking cpu fan. I am going crazy.

I have similar problem with 3700x and stock cooler. We are not first with this issue. I am very sure that in my case, is very good airflow so there is enough fresh cold air to cool down the cpu.
 
My cpu is also jumping from 38 to 55 degree celsius. My utilization of CPU is around 1-5% but temps are jumping for no reason. Its annoying with stock cooler because it is noisy like hair dryer. For me 2500rpm on stock cooler is too much and audiable.
 
 

@linttRaIt is done in UEFI, as described in your motherboard's manual. Or a tool like SpeedFan can be used.
It is easy to do, but hard to explain?

You have to adjust a fan curve for these Zen2 CPUs, they have temperature spikes due to small-sized chiplets.
The heat output of the CPU is not high, but the density is high. I'd recommend a good air cooler, it is more than enough, unless you want water cooling for aesthetic reasons. NH-U12S will be enough. However, some of these CPUs and coolers have non-flat contact surfaces, which leads to heat transfer problems with Zen2.

Update: I ran fire strike 1.1 and scored 24 038. 1st score is 25 603 and the 932nd score is 22 648 so I'm pretty happy with the results. Max temp of the GPU 58c and max of the CPU was 74c at the end

Not great for CPU comparisons but decent enough to see how your PC is doing overall.

Because most people using 3Dmark are using Overclocked systems, and are testing it out trying to get higher scores. Everyone's computer is different, you could build two identical systems down to the screws and still have varying results in benchmarks between the two. If you aren't having drops or issues then you shouldn't worry about it.

Well it's true. If i was only 1k down running stock i'd be chuffed
 
Don't run much stock though ?