See AzerothCore. Basically a cpu optimisation at the cost of ram. Ram is cheap. Toggleable in config.
#
# DontCacheRandomMovementPaths
# Description: Random movement paths (calculated using MoveMaps) can be cached to save cpu time,
# but this may use up considerable amount of memory and can be prevented by setting this option to 1.
# Recommended setting for populated servers is having enough RAM and setting this to 0.
# Default: 0 - (cache paths, uses more memory)
# 1 - (don't cache, uses more cpu)
DontCacheRandomMovementPaths = 0
See AzerothCore. Basically a cpu optimisation at the cost of ram. Ram is cheap. Toggleable in config.