Poor in-game performance for GTX 1070

Hi there,

I have 1070 working fine in OS, in GB (140k+) and other benchmarks show 60-150 fps.

But in game (Fortnite for example or any Steam game) I have 1-2 fps :)

Chess app and experiments like google water working great.

I have latest 378.10.10.10.25.102 web drivers installed and latest CUDA 387.99

What should I do to improve in-game performance?