3D plants - how big is too big?

[Mattheng]

I have been trying to get a decent selection of plants together for my renders.

I looked at the Xfrog freebies but they just melted my computer when I tried to look at them in Vectorworks.

So I scaled back my expectations and went to Google's 3D warehouse, downloaded a few from there and had a moderate amount of success. They weren't perfect but when it's free you can't really complain.

All was fine until I downloaded a 3d Hydrangea that looked great but again the model slowed to a crawl.

Can anyone tell me what a reasonable limit in terms of polygons/mb/whatever the relevant measurement is might be?

Thanks .

Matt