AMD Ryzen 9 7900 's Advantages
Newer PCIe version (5.0 vs 4.0)
Higher base frequency (3.7GHz vs 3.4GHz)
Larger L3 cache size (64MB vs 8MB)
AMD Ryzen 3 8300G 's Advantages
Released 1 years late
Better graphics card performance
More modern manufacturing process (4nm vs 5nm)