Crossfire low performance

Hello guys
Today I downloaded CrossFire and,i'm really surprised because I get fps drops, screen tearing, stuttering, game is unplayable,im on windows10
specs:
i5 6600k
gtx 1060
8 gb ram
ssd and hdd drives
Thermaltake smart se 530W
asus z170-a
That's not my hardware's fault, for example on my old pc : phenom ii x4 840 gtx 750 ti 4 gb ram, game works pretty good.