DPI

I really don't see how DPI could ever affect any of those. The only problem with too low DPI I can think of is pixel-skipping (when minimum mouse read step is too high to move just 1 pixel at low enough sensitivity). The threshold for that depends on your settings (dpi + sens). But it's really easy to test if you have a problem or not: do a minimal mouse movement and see if your reticle moves just 1 pixel or more. If it's more, then you should probably increase dpi (and lower ingame sens to keep it the same).

Too high DPI could result in acceleration, but that's not related to the game in any way, just the imperfection of sensor. I'd say with current sensors, anything up to 3200 or even 6400 dpi is safe (but I can't think of a situation where you would ever need such enormous dpi).

As far as I know 400 and 800 dpi has never been too much or too little to cause problems. I would go with whatever feels best for navigating your mouse cursor and tweaking the in-game sensitivity accordingly.

The thing you really want to avoid is cheaping out on a mouse that has a low malfunction speed. Having a low sensitivity and a lot of surface space is best for most people. You're in the best possible position to make micro-corrections while retaining the ability to 180 with the best of them.

400 dpi can be a problem. At sensitivity I play on (1.5@800 in Apex, haven't tested 400 dpi), I get pixel skipping in all games I tried (OW, pubg). Although, 2 pixels is still enough precision for anything outside very long range shooting, I find 800 dpi to be optimal (I also find 400 dpi to be a bit too low for windows, which is often the same for in-menus (and in pubg's case, in inventory tab) mouse senstivity; that is, if inbetween steps are not available (not on my mouse).

thanks for answers, hit-reg andf latency are not affected by DPI then 🙂