These are all discount brokers. Basically there are trading lines that brokers get which us used by them to trade. So all the discount brokers have their won trading lines which influences their speed.
They use their customized software as trading applications or they can use NEAT (NEAT is NSE software which is fastest) . Very few brokers use NEAT now a days and rest all use their customized softwares. The reason is NEAT has limited functionality.
Answering your question, There will be slight lag in frequency in updation of Orders. However it also depends upon your internet speed and Computer configuration. I have used Kotak Securities, HDFC Securities , Tradesmart online and Zerodha. None compare to NEAT however they all trade with normal speed rather same speed.
Zerodha is preferred because of their brokerage plans and Customer Services.
Visit www.dematguru.com for more details about zerodha.
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