rpm resolution

hello

im making pid motor controller
and have some problem with speed resolution.
im planing to use more ticks per revolution for sensor
so my question is will i get more resolution or faster update with more ticks?

Yes, simply on the basis that the maximum data rate you can get with 1 "tick" is once per rev which for a 3000 rpm motor will be 50 ticks per second (Hz). Whereas if you have 10 markers on the shaft you will get an update rate of 500 Hz

The increase resolution also permits you to detect changes in speed within a revolution whereas if you only measured once per rev, you'd need 2 revs but preferably at least 3 or 4 revs before you could reliably establish a speed change.