Smaller but more meshes or fewer and larger?

So just wanted to check on an efficiency aspect.

lets say I was using the default 400 by 400 floor, better to make 30 copies of it laid out. Or to go ahead and make new versions / setups that are like 1200 by 1200 and use only 10 copies for the level?
Or just one massive mesh of like 3000 units by 3000 units?

unless the mesh has a higher polygon count you spend more resources building stuff like that out of multiple meshes than you would to just make it one big unique mesh. The size limit though is going to be tied to your lightmap resolution, since you can only set it so high you sometimes have to split up meshes to get more detail out of the lightmaps.

Building it modular can mean saving polygons counts since only one object gets loaded into memory, but if it’s just something like a flat floor which would already just be a single quad anyways, then you slow things down by making it out of multiple meshes, that would mean higher amounts of geometry to process and higher draw calls, and you don’t save that much memory.