Configure the router with QoS On or Off as required. Then test using a Speed Test website such as one of these below:

http://tpg.speedtestcustom.com/
https://www.optus.com.au/shop/broadband/nbn/nbn-articles/speed-test
https://www.internode.on.net/support/tools/speed_test/
https://www.iinet.net.au/internet-products/broadband/speed-test/
https://www.ozspeedtest.com/
https://speedtest.telstra.com/