Hi i currently running a dell inspiron 15r 5520 laptop which has a
core i7 3612QM
8gb 1600mhz ram
intel HD 4000 (Integrated Graphics)
Radeon HD 7670m 1gb (Dedicated Graphics)

i have downloaded the latest version of raft but the sad thing is it's running about 8fps  only on 1280x768 res and at its lowest graphics settings.
i have tried every solution such as running it on my radeon hd graphics at max performance and im pretty sure that its running on my radeon hd graphics but still the same.
i have searched it on youtube how it well performs on intel hd 4000 and i saw it running at 25-30fps on  1280x768 resolution and im confused why on my machine it only got 8fps max even though my radeon hd 7670m is way much faster than the intel hd 4000? 
i looked at the gpu usage and i only got 50% of the usage while running raft. i can run CoD MW3 on 1920x1080 max settings but i cant play raft on 1280x768 low settings.
can someone provide me some fix please ?