How to set the capacity of the memory channel ?

[zuo ruochen]

Hello all,
    When i use the memory channel,i am confused with the capacity. In the other 
word, i don’t know the “capacity = 1000” is really represent for. In the user 
guider doc, it says that mean 1000 events, but in fact we always  take 
throughput into account, I really want to know is how many events can be 
processed if i set a capacity.
    Thank you.