Huge frame rate drops after enabling HDR

My setup is i7 8700k + GTX 1080 ti+ 32 Gb Ram. I’m playing in 3840x2160p resolution. On mostly high settings, textures are epic, only anti aliasing is medium. Dynamic resolution scaling off.

I’m getting significant frame rate drops after enabling HDR in video settings.

HDR off: 55-60 fps

HDR on: 38-48 fps

After enabling of dynamic resolution scaling I’m getting stable 60 fps. Also I didn’t noticed any significant downgrade of picture quality using dynamic resolution scaling.

This is the first game, where HDR worsens fps rate.