To enjoy the maximum achievable speed on WIRELESS connection, you NEED to be connected to the 5GHz AC band AND have a suitable router AND a suitable USB Wi-Fi adapter. Your USB wireless adapter needs to be connected to USB3.0 for the best speed achievable on 500Mbps and 800Mbps, as USB2.0 max out at 480Mbps, which makes it only suitable for 300Mbps, and USB3.0 can support up to 5Gbps, which makes it suitable for both 500Mbps and 800Mbps.