How many (low poly) models can XNA handle?

Question

I\'m aware that the following is a vague question, but I\'m hitting performance problems that I did not anticipate in XNA.

I have a low poly model (It has 18 faces a

Answer 1

You're quite clearly hitting the batch limit. See this presentation and this answer and this answer for details. Put simply: there is a limit to how many draw calls you can submit to the GPU each second.

The batch limit is a CPU-based limit, so you'll probably see that your CPU gets pegged once you get to your 5000+ models. Worse still, when your game is doing other calculations, it will reduce the CPU time available to submit those batches.

(And it's important to note that, conversely, you are almost certainly not hitting GPU limits. No need to worry about mesh complexity yet.)

There are a number of ways to reduce your batch count. Frustrum culling is one. Probably the best one to persue in your case is Geometry Instancing, this lets you draw multiple models in a single batch. Here is an XNA sample that does this.

Better still, if it's static geometry, can you simply bake it all into one or a few big meshes?