Intel Core i7 7820X 's Advantages
Higher specification of memory (DDR4-2666 vs DDR4-2400)
Larger memory bandwidth (79.47GB/s vs 37.5GB/s)
Larger L3 cache size (11MB vs 8MB)
Intel Core i3 8300 's Advantages
Released 11 months late
Integrated graphics card
Higher base frequency (3.7GHz vs 3.6GHz)
Lower TDP (62W vs 140W)