If Pd's default block size is 64 samples, and "events" are only processed at the beginning of a block cycle.

Therefore, if you're running at 48,000hz sample rate, then your "Event Rate" is 750hz.
Likewise a 96,000hz sample rate will give you a 1500hz "Event Rate".

As Mathieu mentioned, if you need anything higher than this, your only options are:
  1. Decrease your block size
  2. Calculate at audio-rate using ~ objects
As for "between samples", are you referring to some kind of upsampling?  In that case, either increase the sample rate of a sub-patch using [block~] relative to the current sample rate, or use either a [delread~]/[delwrite~] pair or [fexpr~] to hold the last sample value from a given stream for calculation.

~Brandon