Default Nexus 5 WiFi performance, high end hardware

Hi guys,

I have wifi performance issues with my Nexus 5 in combination with all routers. When running ac at 433mbps I get 45-60mbps on my download speeds. My internet speed is 180/18 so the 433mbps wifi should atleast perform in the same manner. I have tested my wifi connection with a manual dos tool (can't remember the name) and it gave 240mbps download and 160mbps upload on my local network. For internet speedtesting im using the speedtest.net app. Any other apps are also giving me 45-60mbps download and 17,8 upload. My normal internet performance hits 180/17,8 without issues.

I'm using the Asus RT-AC68U. Any suggestions on this issue?

Thanks in advance.