it happens in all projects without exception.
All demo scene which has opened the market of mourning
it automatically compiles shaders for every scene change (landscape or material). Lighting is calculated quickly and without problems. Project 63h63.
there is always a problem. even when done an empty landscape and imposed on him multylayer material
Have you changed your GPU power management settings within the nvidia control panel? Check the control panel to see if you are set to save power or if you are currently using the maximum performance from the card.
if you look closely watched screenshots, you would understand that the card operates at a maximum when this from her trebuyut.a ue4 editor does not require it.
Shader compiling occurs on the CPU which is why during this process your GPU is not returning full usage. You are not graphically taxing the GPU, at least in that screenshot you have provided.
Take a read over the post below to read more about how this works.
Hopefully that clarifies your question in regards to why your GPU is not being used at the max percentage. There are other factors that add to this as well.