Dynamic batching not working with direct X?

Hi guys, I have a weird issue with dynamic batching. In my current project I use Texture2D.PackTextures to create texture atlas, uv-map and shared material for batching purpose. Everything works fine with OpenGL, stat's editor shows number of drawcall saved by batching. But when I force unity run with DirectX, bathing doesn't work anymore, 0 drawcall saved showed at stat's editor. I read unity's document carefully about dynamic batching(all theirs conditions) and cant find anything that noted dynamic batching is relied on graphic library.