From what can the system lag?

Question

Windows

Microfreezes appeared, as if the system was puffing with all its might.
Fresh OS installed on ssd 31.05.2021. Assembly 19042.572 There were no complaints before and after (until today).
2 monitors. All frequencies and voltages are stock.
In idle time on resources, a maximum of 1-3% is occupied. What alerted me:
the stone spins 4.75 GHz and 51.9 GB of RAM is allocated (maybe I didn’t pay attention before)

In heavy applications, frames walk 110-144fps (when downloads are less than 20-40%), although earlier fluctuations were up to 10 frames
What you can check / see ? The first time I encounter unreasonable (in my opinion) brakes

-CPU: Intel Core i7-9700K
- GPU: RTX 2060 SUPER
- RAM: 16(2x8GB) DDR4 3200MHz Kingston
- MB: ASRock Z390
- SSD NVMe for Windows: Smartbuy E13T Pro (256GB)
- SSD for Data: Intel S3520 (480GB) x2
- HDD for Data: SEAGATE Barracuda (1TB)
- OS: Windows 10 LTSB

Answer 1

upd. thanks man for the advice to try Latencymon.
With some fright

msmpeng.exe

I decided that everything was possible for him and began to scan in real time.

Answer 2

what does the task manager show? What is the RAM and CPU busy with?