If you place your orders for HK/Asia products to our US server, the first leg would be via commodity internet (which in your case would add about 350ms-180ms=170ms, then the order would travel inside IB's network back to our HK servers which would add roughly the same (I don't have any real numbers, so this is just a guesstimate).
Thus you're looking at about 340ms additional delay if you were to place HK orders thru IB's US servers as opposed to placing them into IB's HK servers.
Thus you're looking at about 340ms additional delay if you were to place HK orders thru IB's US servers as opposed to placing them into IB's HK servers.