if you are a gamer, just buy the 5700X3d you will have way more gaming performace with it, but if you need more cpu power for work then the 5900x is the way to go, i went from a 1700 to the 5800X3d and the performance increase was crazy, specialy after i bought a Red Devil RX6800XT Now i play 1440 ultra without any issues
Ryzen 7 5800x3D - Powercolor RX6800XT Red Devil - 16GB Ram - MSI B550 Gaming Plus - Win 11 / AMD R7 1700 - PowerColor RedDevil RX580 8GB - 16GB Corsair Vengeance LPX - MSI x470 gaming plus - Win10 and also Phenom 9950 Black Edition 8gb Ram - HD7870 2GB