Replication of arrays, overhead vs non arrays?

Not sure which forum to post this under, since there’s no network related one…

Does anyone know how arrays are replicated vs single variables?

For example when I change 1 value of an array with 8 keys does it replicate the whole array or does it only replicate the change to that one key? I’m trying to optimize my game for as many players as possible and little things like this could have a HUGE impact on bandwidth usage.

It’s supposed to only replicate the changed item, AFAIK. Likely with an Index too to tell the receiver what array item it is that’s changed.