ca. 1300 static meshes (spheres) - optimizing rendering

Hey guys,

I am building a fairly simple prototype that basically only spawns 1300 spheres from a csv-sheet.
The spheres are blueprints with some logic applied to them. Mostly they have force applied to them. The force pulls them to a gravity-center where they create a big “blob”.

When I am standing some meters away it’s all fine. But when I go closer it starts to lag like crazy.
I was thinking it has to do with higher quality rendering when I am closer - opposed to less quality when I am standing further away.

My question: what are the options I have to lower the quality of the rendering for the spheres to see whether the visual quality is what causes the performance-drop?

thanks alot in advance!

Note: I am new to UE4 and making my first prototype, so even obvious answers might help!

Press F2 in game, this will switch to unlit render, which is simple as possible.

To understand where it lags use ptofiling.