In RTX beta version RTX2070 can't be fully used

In the RTX beta 1.15.0.8 version, RTX2070 can't be fully used. When I set the picture quality options to the highest, the fps of the game is about 20-30fps but my RTX2070 just be used about 10%.

I have upgraded my driver to the newest version. I think if my RTX2070 can be fully used, the fps will be much higher. So I want you can fix this problem