I recently built my first new PC with these specs:
Processor: AMD Ryzen 5 1600
Graphics card: nVIDIA GTX 1660 Super GDDR6 6GB (PALiT)
RAM: HyperX Furry Black DDR4 4GB 3000Mhz (2x)
Motherboard: GIGABYTE B450M S2H - AMD B450
Power supply: Corsair CV Series CV550 - 550W
HDD: WD Blue (EZEX), 3,5" - 1TB 7200RPM
And in some games, namely: GTA V, Star Wars Battlefront II and AC: Odyssey I experience big FPS drops. But in all games a little differently.
GTA V: Runs flawlessly 60 FPS in story mode. In Online runs flawlessly 60FPS for circa 10 minutes and then big FPS drops with sound stutter (CPU usage: 19-21%, GPU usage: 10%, RAM usage 90%, HDD usage 100%)
Star Wars: Battlefront II: At a start of a game or new map it lags like crazy 10-25FPS and long frame times, then runs smoothly for the rest of the session (CPU usage: 46-50%, GPU usage: 98-100%, RAM usage: 95%, HDD usage: 100%)
AC: Odyssey: Random drops in FPS and when Fast travel is used then it starts to drop very often until restart
I really have no idea what can be causing this. I dont think its the GPU or CPU. I was thinking that the HDD is too slow to load such big games.
Thats why I am here, to ask more experienced people for a clue.
Also one big thing that i forgot to mention, my brother has this exact same build. The only difference is that he has nVIDIA 1060 6GB, slightly different motherboard and different HDD. And he is not experiencing any of these problems.
Ill be gratefull for any help or response!
PS: Sorry for my English, I am from Czechia!