AMD Ryzen 7 6800U's Advantages
Lower TDP (15W vs 15W)
AMD Ryzen 7 8840U's Advantages
Released 1 years and 11 months late
Better graphics card performance
Higher specification of memory (LPDDR5x-7500 vs LPDDR5-6400)
Larger memory bandwidth (89.6GB/s vs 76.8GB/s)
Higher base frequency (3.3GHz vs 2.7GHz)