DX12 works better than DX11 for me but

On DX11 my FPS on Ultra goes down to 45-60 and plays kinda sluggish so i have set it to DX12 beta and for some reason my FPS goes up to 60-75 FPS but the game still feels sluggish at times ( while the FPS stays at 70 fps ) why is this?

Also the loading takes up to 3 minutes when i set it to DX12.

i7 4790k, 16g ddr3 1666mhz, GTX 1070 g1 gaming, W10, SSD.

lucky you, takes me likem 6min + to start up with dx12 and its because the game just runs like ■■■■ and dx12 is experimental since they couldnt be bothered finishing it before launch