Why do market orders and AMO orders delay execution at 9.15 when the market opens?

When I place orders at market opening (exactly at 9.15 am), it seems to be taking time to execute. This is the same with both market orders placed exactly at 9.15 am and also when I use AMO (after market orders) which is supposed to execute at open. I am facing the issues with both Zerodha and Sharekhan accounts. Can someone tell me why and what can be done about this.

Essentially two things determine time taken for the order execution speeds at the opening of the market.

  1. Exchange capacity to handle orders, NSE has a capacity to process around 50,000 orders per second. If more than that hits the exchange, orders get queued up. Usually the first few seconds, lakhs of orders could be getting placed which can get in a queue and take some seconds to execute.

  2. Order queue from the broker. Every broker is connected to exchanges via leased lines. These lines have a certain order per second capacity, if more than those are sent, they get in a queue and can take a few seconds.

When the market just opens, either of the two could be happening that can delay order execution.