How important is mouse DPI in games?
Solution 1:
It depends on your monitor resolution. Larger monitor resolutions have more pixels (or dots). So, for example, if your screen resolution was 1920x1200 and your mouse was capable of a maximum DPI of 600, you'd have to move your mouse two inches to get to the bottom of the screen to the top of the screen. If your mouse was capable of a DPI of 1200, it would only take one inch to make the same movement on the screen.
In short, as long as screen resolutions keep increasing, mice resolutions will need to continue to increase as well to prevent people from having to move their mice uncomfortable lengths to cross the screen.
Solution 2:
I currently run at 3200 because that's what I feel is comfortable.
You only need as much sensitivity as makes your hand feel comfortable.
If you find that you're picking up your mouse a lot and getting fatigued, you should probably use a higher DPI setting/mouse.
My low setting is 1k which is what I set it to when I deign to let others touch my computer.
If I had larger screens, I'd probably consider bumping up to 4k+.
Solution 3:
Higher DPI settings allow you to move faster on the screen with less mouse movement, or increase precision by using reduced sensitivity in conjunction with higher DPI.
Higher resolution displays require higher sensitivity or higher DPI to attain the same amount of on-screen movement, and higher sensitivity settings with a low DPI mouse can limit precision. This is manifested by movements occurring in increments of more than one pixel, making it difficult to precisely aim or otherwise make fine movements. Higher DPI allows you to increase movement speed without increasing the sensitivity setting, giving you more precise control.
Note that this really isn't that big a deal with a lower resolution display. I use a ROCCAT Kone XTD, and I have the mouse set to 1800 DPI with sensitivity at -2 (on a scale of -5 to +5). This is on a run-of-the-mill HP laptop with a 1366x768 display, so DPI settings much higher than this (up to 8200 DPI) are essentially unusable for me. Higher DPI will definitely make a difference on larger displays, though.
Solution 4:
DPI is really just how fast your mouse cursor moves at all times, whether you're playing a game, surfing the web, working on word document, etc. Yes it depends on your resolution, but that's relativity.
There is a term "eDPI" that gamers use to communicate how fast their sensitivity is. You get eDPI by multiplying your mouse DPI by your game sensitivity.
For example my Razer Deathadder has DPI of 800, and in Overwatch my sensitivity is 5. So 800 * 5 = 4000. When I talk with other Overwatch players about sensitivity, I say that my eDPI is 4000.
Source: Overwatch Pro Settings & Setups