AMD Ryzen 9 5900H 's Advantages
Lower TDP (45W vs 54W)
AMD Ryzen 7 7840HS 's Advantages
Released 2 years late
Higher specification of memory (7500 vs 4266)
Larger memory bandwidth (89.6GB/s vs 68.27GB/s)
Newer PCIe version (4.0 vs 3.0)
Higher base frequency (3.8GHz vs 3.3GHz)
More modern manufacturing process (4nm vs 7nm)