World Composition Landscape Performance Issues

The tiles are 505x505 pixels and have 16 components per tile as that is the lowest the editor will allow me to choose in World Comp.

Specs:

16GB RAM

AMD FX-8350 Black Edition CPU

PNY GTX 1660 XLR8 GPU (Factory Overclocked)

Windows 10 64-bit

All drivers up-to-date, project stored on 3tb HDD, but no difference when loading from SSD.