I think that it might be your broker, or your latency to your brokers server, or their latency to their LP.
We literally execute many trades per second in MT4 in our personal autotrading systems, and perhaps more than that since we trade many many systems together, so our "mother" system is constantly adjusting positions.
Seriously, if people that saw the number of trades we execute personally, they would call us insane. We used to go direct to API, but since our new arrangement, we funnel through MT4 and don't see any slowdown really to speak of. We did however relocate trade servers close to our execution server, and LPs.
2 seconds is quite ridiculous, and not related to MT4 at all.
Check your latency to your live server, then ask your broker to report their latency to their LP's. Therein lies your problem, and hence solution.
Trader 5of7 @ TheCollectiveFX.com