How many Actory can you spawn? 20k seems too much for UE4?

Hello everyone! Here is my problem:

I need 20k Actors with only a static mesh (A low poly plant) in each of these actors.
I need this, so I can make them disappear when I place something on them (like a house).
I thought Unreal could handle 20k actors but my fps drop to 5.
100k of only the static mesh isn’t a problem at all, so it is not the mesh.
I haven’t touched the actor at all besides adding the static mesh component, so it can’t be some dumb code of mine.

Has someone any experience with huge amount of actors? Is it even possible?
And if it is, what am I doing wrong?

My Pc is also “sleeping”, no peaks in CPU or GPU while doing any of this.

PC Specs: GTX 1080 TI
AMD Ryzen 7 2700X
All running on a M.2 SSD

Thanks for your help!

That’s probably because you aren’t using instances.

On such a large sample you likely want to use the HISM (hierarchical instanced static mesh) component.

A viable (maybe better, in my experience the occlusion works much better for it) alternative would be to just create a foliage brush with the mesh and paint it onto a mesh you can then delete.

As long as you aren’t dealing with animated skeletal meshes, this should be trivial.