I'm working on geometry sorting by material, distance, and transparency. So far I have a sort key that I plan to perform a radix sort on to sort by material ID, distance, and any other factors I might want to add. What I want to know though, is once I have this sorted, do I have to manage whether or not draw calls happen on my own? Once the list of renderables is sorted, is there a draw call cost associated with setting the same vertex shader for each object in the sorted list? For example: objects 1,2,3, and 4 all use the same shader. Once I've sorted, do I need to set the vertex shader only when I reach 1, without calling VSSetShader on the next ones to benefit from the sorting? Also, if I do have to prevent duplicate calls to VSSetShader, wouldn't the conditional statement to check if the current shader is equal to the one being set give me similar overhead? I would think there's some sort of safety check in either the DirectX API or the driver that would avoid loading the shader to the GPU if it was already set.