Performance on AMD build

My build is ryzen 7 7800x3d, 32 gb ram ddr5 , gpu RX 7700 XT 12GB. While most times i do get the FPS cap i set at 120, there are a lot of time that i get dips into 80 and more rarely 60 fps, which last for more than few seconds. I'm not 100% sure but on maps with weather effects have seen it more often.