Network communication rate

How much is network latency per byte in epiphany chip?
I use e-get-global-address to find other core array, but ot seems that has a lot latency. How much should it be?
which points should consider when using noc in order to being efficient?
Thanks
I use e-get-global-address to find other core array, but ot seems that has a lot latency. How much should it be?
which points should consider when using noc in order to being efficient?
Thanks