Question FPS spike lags or FPS drops on new high end pc build please help

Feb 10, 2021
Hi, I need some advice from you because I have a minor problem. I have a new pc build where it is

- ASUS RTX 3090 strix OC

- I9 10900K

- HyperX fury rgb 32gb ram 3600mhz

- Samsung ssd 970 evo plus 1tb abd 250gb

- 1tb seagate hdd

- asus rog maximus XII hero wifi

- asus rog ryujin 360

and asus rog thor 1200w

Monitor: Asus rog pg279q 165hz 2560x1440

And the problem is that when I turn on any game, I have drops of fps at high fps. This means that when I turn on Fortnite, for example, my graphics settings run around 180-210 fps. But in a while it drops to one millisetin at 80 fps and back to 200 and this makes it visible lag. Same tomb raider. Everything runs with vsync between 140 and 165 fps mostly at 165, but it does small lags for this very reason. I have G sync turned on and I also use directx 12. Can't do directx 12 or untunned graphics card drivers when they're still new? I used Asus gpu tweaker 3 and then 2 and now I use msi afterburner. I didn't do anything with CPU clocking, I just use xmp I profile because i dont want have 2400mhz but i want my 3600mhz. Thank you in advance for your answers, help and opinions. I will be very happy if it can be solved or at least somehow discover what the problem is.