Someone tell me the difference low sense/high sensitivity gaming?

Originally Posted by hullohihello 

So the way it works is that the mouse has a built in dpi, for how many pixels it will move across the screen for every inch you move it on the mousepad. Game sensitivity adjusts this by using an algorithm to adjust the "effective dpi" by skipping pixels or keeping the cursor on the same pixel. This mainly helps with some non-adjustable dpi mice being able to have approximately the dpi one wants but comes at the cost of accuracy. For example, 6/11 mouse speed is standard windows mouse speed, but 8/11 is double speed, skipping every other pixel on the screen to make the mouse appear to be acting as if there was double the dpi.
With that being said, it makes no sense to turn the dpi really high and game sensitivity really low since that would be less accurate than having ideal dpi and then game sensitivity off/default. For competitive gaming, I've seen as high as 3000s (but normally closer to 2000) for professional RTS like starcraft where speed is more important that accuracy, but in fps games, usually dpi is below 1000 to allow for longer (and thus more accurate) movements. Anything over 3500 dpi is really just marketing hype and has no practical purpose as you'll see most pro gamers using standard high dpi optical (at least in sc2) with 3500 max dpi, which is then tuned down.
With that being said, mice are supposedly less accurate at the edges of its dpi range, so if you plan on using 1800, maybe 2500+dpi maximum is what you should be looking for if you're a really serious/professional gamer.