how to maximize access point speed? from 178 mbps to 800 mbps

i have some APN0204 Access Point, using Instant Virtual Controller. However, when a user is connected to the AP, the maximum speed can only reach 178 Mbps, while the AP capacity can reach 800 Mbps. Is there a setting that can maximize AP throughput?I've tried connecting from the laptop to the AP, it's only 178 mbps, but if I try to connect to another AP brand (like Prolink) it can get 800 Mbps