There should be a option in your driver where you can select high/low performance for applications. If you can find it and set the application to high performace, than it should use your r7 card.
I have already done that, but I don't have some specially results. Its the same problem. I think that there is a problem with drivers, I tried to update them but its same all the time. I tried also to install the previous version and little bit older version of drivers, but same problem all the time. I looked for drivers on AMD support page, but I couldn't find some solution on about the problem. I'm using Windows 10. So if anyone had this problem and fixed, tell me. I'll appreciate that.