Big meshes, big drop in performance, memory issue?

Unity Engine
1

So, I was wondering how a mesh collider would perform on a large mesh of about 64,000 triangles, 33,000 verts and so I ran a test. It actually turned out, that the collider caused about no difference in FPS. However, the mesh itself, caused a huge drop from 60-65FPS down to 27-31FPS. This is running on Unity 3.5, with a 3.5Ghz CPU, 16GB RAM + 2GB VRAM. I also tested as a build, with same results.

So this leaves me to believe Unity is hitting performace problems with RAM possibly. Because even when the mesh is frustrum culled, the FPS is the same. This is very disappointing. I heard there was a 2GB RAM limit for Unity, is this the case? And do you agree this is likely the issue? Any plans to increase this out dated limit?

2

It’s not “Unity” limit, it’s 32bit limit. They will probably ship 64bit editor at some point anyway.

You can still have 64bit player now.

3

Tested as 64bit, same result. I don’t understand why it’s such a huge performance hit.

If I duplicate the mesh w/ collider it drops a few more FPS but not much.

4

This is worryful. Hoping I’m just missing something.

5

I just put a high poly cube from Blender into Unity 4.x and I’m not seeing the same results as you. Everything runs smooth at my end.

Do you have any sort of scripts running or is it just your mesh? Default shader? Textures? Lights?
give us more information.

Are you willing to share your mesh? Maybe there is something wrong

EDIT: or do a build with the FPS counter from the wiki and upload it.

6

AH! I had lot of raycasts hitting it, turning that off did the trick for frustrum culling for some reason.
However I was still getting 30FPS within the frustrum. I noticed I had floating point precision warning. So I scaled the mesh down, and it now runs smoothly. Why would the floating point precision cause such a big hit?