   D3DXCreateMesh fails when faces and vertices are large?
  I create DX mesh use D3DXCreateMesh(43000, 72000,D3DXMESH_MANAGED, VertexDecl,pDevice,&pMesh); it fails to create mesh and pMesh is null. When first and second parameter are samll it succeed otherwise fails. My mesh is large then how to solve this problem? Thank you.   
  Use the D3DXMESH_32BIT flag to get 32-bit indices instead of 16-bit indices.   ;  Thank you, I see.Use D3DXMESH_MANAGED|D3DXMESH_32BIT instead of D3DXMESH_MANAGED only. A 32-bit mesh (D3DXMESH_32BIT) can theoretically support (2^32)-1 faces and vertices. However, allocating memory for a mesh that large on a 32-bit operating system is not practical.