Terrain poly count advice?

I'm experimenting with some large terrain files generated in Vue Infinite and I'm wondering if someone with more experience building outdoor levels might offer some advice.

The scene I'm building features a castle on a craggy promontory overlooking a rocky, uneven valley, dotted with lakes and surrounded by mountains.

What is the upper limit of polys I should be allocating to the terrain? Is 100K too many for a game aimed at higher end machines?

 

As with anything it depends on how much of that is on screen at one time. AFAIK you can only properly import models that are less than 65K or so, but I too have dropped a 100k terrain in without issues. Someone else will have to tell you the exact limits.

It would be best to break that up into several pieces so Unity can cull it more efficiently.

For me, a 100K+ terrain with a 4 layered shader on a GeForce FX 5200 (64mb) and a dual G5 machine runs around 25fps. Considering my card is horrible, that's not to shabby.

Edit: In my test level, I could also see about 2-thirds of all that on screen at once.

HTH,
-Jeremy