i7 8700K vs i5 8400 - cpu comparison for Gaming

Specs

i7 8700Ki5 8400
Average Price$389$178
BrandINTELINTEL
Cores66
Threads126
Base Frequency3.72.8

Gaming performance (working with gtx 1080 Ti, Ultra quality)

FPS (i7 8700K)FPS (i5 8400)
destiny2 135.4126.2
overwatch 178.2165.7
GTA 94.687.6
DOTA2 183.1171.2
CSGO 275.9257
Warframe 190.8178.2
rainbow6siege 110.2102.1
Fortnite 143.8134.1
Sea of Thieves 146.8136.6
A Way Out 152.3141.8
LOL 250.7233.6
Far Cry 5 119110.9
PUBG 9386.8
Call of Duty ww2 157.1146.8
Radical Heights 104.397.2
Battlefield 4 74.469.3
World of Tanks 77.572.2
apexlegends 113.8106.1
Path of Exile 174.8162.9
Frostpunk 145.7135.8
BATTLETECH 95.188.6
AirMech Strike 142.7133
StarCraft 2 166.5155.2

Conclusion

Price to Performance: i5 8400 is better. (54% Lower on Price, 7% Lower on performance.)

All resources

Games:
AirMech Strike Apex Legends A Way Out Battlefield 4 BATTLETECH Call of Duty WWII Counter-Strike: Global Offensive Destiny 2 Dota 2 Far Cry 5 Fortnite Frostpunk Grand Theft Auto V League of Legends Overwatch Path of Exile PlayerUnknown's Battlegrounds Radical Heights Rainbow Six | Siege Sea of Thieves StarCraft 2 Warframe World of Tanks
GPUs:
gtx 1050gtx 1050 Tigtx 1060 3Ggtx 1060 6Ggtx 1070gtx 1070 Tigtx 1080gtx 1080 Tigtx 2070gtx 2080gtx 2080 Tigtx 970gtx 980gtx 980 Tigtx Titan XRX 480RX 570RX 580RX Vega 64
CPUs:
i3 7100i5 7500i5 7600ki5 8400i5 8600ki7 7700Ki7 8700KRyzen 3 1200Ryzen 5 1600Ryzen 5 1600xRyzen 5 2600Ryzen 5 2600xRyzen 7 1700Ryzen 7 1700X