But for performance summary....I dunno I think it makes no sense
Come on, dude.
Card 1 vs Card 2:
game 1: 50fps 100fps => 200%
game 2: 100fps 50fps => 50%
Wow, card 2 is 25% faster than card 1!
Oh, but what if we compare them other way round?
Card 2 vs Card 1:
game 1: 100fps 50fps => 50%
game 2: 50fps 100fps => 200%
Wow, card 1 is 25% faster than card 2!
Amazing stuff eh, both cards are somehow 25% faster than each other!!!
That's why arithmetic mean makes no sense.