Intel Core i5 8265U's Advantages
Better graphics card performance
Higher specification of memory (DDR4-2400 vs DDR4-2133)
Newer PCIe version (3.0 vs 2.0)
Larger L3 cache size (6MB vs 2MB)
Intel Pentium Gold 5405U's Advantages
Higher base frequency (2.3GHz vs 1.6GHz)