hmm, I've never really had a performance problem with under 11,000 faces, even on my Pentium 2 400. (what system do you have and what video card?)
If you post a screenshot that might help. Also depends what else you are doing, collisions and linepicks are a killer if your doing it on a lot of polys.
If you post a screenshot that might help. Also depends what else you are doing, collisions and linepicks are a killer if your doing it on a lot of polys.