Insofar as gender is a social construct and potentially unique to a person, one could say that gender’s maximum file size would be equal to an entity’s conceptualization of their gender. While you might be able to parse out the “gender” portion of a standard human brain by mapping the various neural connections’ patterns that form the basic archetypal building blocks that eventually model gender through their activation in series, that excludes the possibility of a non-human brain that could have a much more defined, complex conceptualization of gender. While there is likely an upper limit given inherent physical limitations in the emergent phenomenon of sapience, there is much yet to be explored in this topic.