Why does my mouse move faster in game?

I have a razer deathadder chroma, and I configure it to be about 5000 dpi for everything else. But if I go into league with this setting, it starts moving much faster. This happens even if I have the game setting of mouse sensitivity at 0. I need to make it to like 2000 dpi for it to be moving at regular speed.

Is anyone else having this issue or does anyone know a solution?