Bad Jim said:
Regular mice generally have limited resolution. If your mouse sensitivity is low enough that you can aim precisely, you'll probably need to move it a couple of feet if you want to be able to turn around. Or you can suffer mouse acceleration, where your mouse sensitivity depends on how fast you move the mouse, which allows you to do both but it's much harder to do twitch shots because you cannot move the mouse a specific distance and have your crosshair move by a specific amount.
Higher sensor accuracy is an advantage of gaming mice, but it has nothing to do with the dpi of the sensor. Laser mice generally have much higher DPI than most optical mice, but all Laser mice have a degree of acceleration. What's more, the Intellimouse optical only runs at 400/450DPI, but is very highly regarded for it's performance.
Gaming mice have much better resolution and can also increase the polling rate, which has the interesting side effect of almost nullifying the two-speed mouse acceleration that Windows uses,
Polling rate has no effect on windows cursor acceleration. It simply refers to the number of times per second that a mouse sends information to the computer. The only two ways of nullifying windows cursor acceleration are by using a third party fix, such as the MarkC mouse fix, or if a game supports raw input, which bypasses windows mouse settings.
as it becomes hard to move the mouse fast enough to trigger the higher mouse speed.
While the Wheelmouse Optical and Intellimouse explorer did gain a higher max-perfect control speeds when raising their polling rate, most mice have such flawed sensors that raising the polling rate has no real positive effect on performance.
Bad Jim said:
No. The DPI on your mouse is not the same as mouse sensitivity. It is true that the most noticeable effect of increasing DPI is increased mouse sensitivity, but the real benefit is greater precision. Throw out your 400 DPI mouse, get a 4,000 DPI mouse, then use in-game settings to reduce your mouse sensitivity by a factor of ten. Overall, your mouse speed will be the same, but you can be ten times more precise with small movements. And this is true even if your mouse mat is a metre wide. As long as in-game settings allow you to lower your mouse sensitivity far enough, you are always better off with higher DPI. It's like framerate.
Wrong.
tl;dw
All mice, including gaming mice, achieve a higher DPI by multiplying the number of pixels moved for every inch of movement that the sensor moves. This makes the mouse
less accurate, not more.
At very (read: stupidly) high sensitivities, some games will start skipping whole pixels, but this has less to do with the mouse and more to do with how games handle turning. Any perceived gain of accuracy is purely a placebo.