most of the tester will use pcs of today so I made a test with my old pc for surfing etc.
amd 3400 64bit ( so 2,4 ghz)
nvidia 6200TC

it's a really old pc, (1gb ram lol)

so mmo_crowd.exe was around 7 fps (both in windowed and fullscreen plus it started around 13,12 fps)
and mmo_terrain.exe was around 4 to 6 fps ( again in wondowed and fullscreen mode)

I know my pc is old ( I still test everything on this pc i like it to see the difference to nowadays pcs)
hm good luck with your own renderer

this appart did u take a look into Horde3D ?
ok it's build uppon opengl but maybe you could have some ideas from it. it's open source (and they changed the license, now its less restrictive than before). I remembered a demo of Horde3d and it was good for rendering a lot of models
simultaneously. maybe some ideas of how they handle it, is useful even if it's implented on opengl.

nice greetings