I’m hoping there are some hard-core gamers lurking in this subforum that might know the answer to this.
I recently bought a mouse with a high dpi setting (roccat kova). I want it set on its highest so that I am (I assume) getting the best out of it. but the pointer is way too fast so I lower the sensitivity setting in windows and games.
My question is - by lowering the sensitivity am I undoing the extra accuracy obtained by the high DPI?
I am hoping that by slowing it down I am simply altering the algorithm that controls how fast it moves, rather than altering the DPI.
(user of high-end drafting hardware)
My WAG is that the OS sensitivity setting probably doesn’t affect the sensitivity of the mouse’s sensor. The DPI of the mouse is referring to the sensitivity of the optic on the mouse, so that it can read very small position changes of the surface it is on. IOW, a higher DPI mouse isn’t going to move faster on your screen relative to a low DPI mouse given the same OS settings, but it will be much less prone to “stickiness” or confusion from your mousepad surface and should (in theory) more accurately translate your physical movement into the cursor movement.
In my case, I wouldn’t think it would matter so much in action gaming, but if you are very slowly trying to draw an accurate curve in a drawing application, you want the output on the screen to be as smooth and un-jaggy as the real trace drawn by the mouse.
Otherwise, it is finding your sweet spot of the settings that feel best to you when playing.
The slow accurate movement comes into play when sniping or just general aiming.
Wouldn’t a graphics tablet be better for your curve drawing needs? 
EDIT: I might try a graphics tablet for gaming 
. In it’s normal mode it will just cause the player to spin when the pen is not in the middle - but tablets come with a mode that simulates mouse movement, so wherever you put the pen down becomes the center, and moving from that point tracks in software. So in theory that might work in a game.
Generally, DPI is basically how many pixels your mouse can move in one inch. The higher the DPI, the faster you can go. So it’s basically the same as sensitivity. Windows can mess with this by either doubling the movement per count or ignore counts, which is how Windows changes the sensitivity. By lowering the sensitivity in Windows, you’re undoing the “accuracy” of higher DPI.
If you want to get the most of your mouse, you need to set it to what you’re comfortable playing with. I haven’t seen you play, but I know right now that you’re not physically capable of controlling the mouse accurately at those high DPI settings. Don’t take it badly. I’m not either. No one is.
How most people I’ve seen at events and how I do it when I’m trying to be all serious business about it is at ultra low sensitivity. Something like 25 inches of mouse movement for one rotation. I use a giant QcK+ mousepad and it takes about its full length to turn around. If I need to rotate slowly, I can move slowly. If I need to move quickly, I can move quickly. It all comes from the elbow though. If you’re running a crazy high DPI, you don’t really get the option of slow.
The problem at this point though, is when you’re moving so quickly, you start running into trouble with the fail speed of your mouse. DPI doesn’t matter for that. That’s an issue with the sensor in your mouse.
Oh, and since I didn’t really say it and it’s important: the buttons for DPI on your mouse are just changing the sensitivity the exact same way Windows does it, only it’s happening at the driver level. It doesn’t really improve the precision of your mouse and probably takes away from it. How many “counts” your mouse makes is what matters.