Duplex is always VERY effective and unless there's others gaming and running videos, QoS is useless buddy.Duplex will not change your results much, That would be QoS or Quality of Service, some routers have the option while others do not. Even if the router has the option it doesn't always have the option to adjust total bandwidth distribution and even then it doesn't always work out the way you want it to. That said, you're looking for QoS, good luck with it