Intel Core i7 8665U 's Advantages
Lower TDP (15W vs 45W)
Intel Core i7 9750H 's Advantages
Higher specification of memory (DDR4-2666 vs DDR4-2400)
Larger memory bandwidth (41.8GB/s vs 37.5GB/s)
Higher base frequency (2.6GHz vs 1.9GHz)
Larger L3 cache size (12MB vs 8MB)