Question rx 570 not performing well on Forza 4

[MARV23]

So my rx 570 wont get near 60 fps, 45-60 fps while gaming, im pretty sure it can run fora horizon 4 in ultra and get a stable 60+ fps

Graphic settings
Ultra but i diabled the msaa

RX 570
I7 3770 4.1 GHZ
2X4GB DIFFERENT MODELS BUT SAME SPEED 1600MHZ

 

[rgd1101]

what resolution?
what the cpu/gpu temp and usage during the game?
ram usage?

 

[MARV23]

what resolution?
what the cpu/gpu temp and usage during the game?
ram usage?

1080p
My cpu never exceeds 70c and has 60-65 avg (utilisation :50%)
Gpu also doesn't exceeds 70c and with an avg of 62-65 (utilisation :100%)