Windows' beautiful curse.
Mouse Negative Acceleration comes free with every copy of windows and without you knowing, hurts your aim. Let's say right now you "know your mouse" only because you dont know any different. Well when you snap your mouse real quick there is negative acceleration. Ever try to turn real fast because someone jumped out in front of you and your mouse wasn't "there" for you but your muscle memory knows you made the correct movement? That was negative acceleration. You moved so fast that it under-performed. Removing the negative acceleration will allow a True 1-to-1 movement ratio like you Thought you had. Thankfully several people over the years have created fixes such as Cheese fix and CPL mouse fix. MarkC has compiled everything into a nice package and has even gone ahead and included windows 10.
Find the display DPI that you currently use:
Click Start, click Control Panel, select Appearance and Personalization, select Display.
See if you have 100% or 125% or 150% selected.
Open the ZIP file at the link above.
Select the folder that matches the Windows version you use and Double-click it.
Select the REG file that matches the DPI% you use and Double-click it.
Answer Yes, OK to the prompts that appear.
Open Control Panel and goto Mouse Settings
Under Pointer Options move the slider to notch 6 / 11 or This Will Not Work
Slider spot number 6 (middle) is the only slot that will give true 1-to-1 Movement.
Reboot or Log off to apply the fix (you have to reboot or Log off).
Enjoy exactly 1-to-1 mouse to pointer response!
(If you applied one of the Windows 2000 or Windows 98/95 Acceleration fixes, then 'Enhance pointer precision' must be checked ON to enable it.)
*NOTE* 1000hz on an AMD Phenom x4 965 I can pull 8% CPU usage with my mouse. Assuming modern CPU's can handle any refresh rate is a myth, test for yourself, lag spiking during a firefight is not a good idea.