You can overclock and change what you want, the bottleneck is your 3G VRAM.
FM7 needs more than 3gb @ 1080p, no matter what quality settings.
Check the utilization on your machine to see it by yourself.
If you want solid 60 FPS you need to change something that really effects the VRAM (= lower resolution !!!).
Turn10 doesn’t say minimum of 4gb VRAM for 1080p for no reason.