I had the same issue. upgrade from 10mbps to 30mbps. Previous 10mbps was consistently getting 9-10mbps. Which is good.

With the newly upgraded 30mbps, I got 18-22mbps wifi.
Remembered that a friend said he got 18mbps with wifi, but with wired LAN, he can get 30mbps consistently.
I tried mine with LAN cable too, it worked! ... getting 31mbps consistently. Lucky!
*Tested on both Unifi Speedtest and Speedtest.net

Now I'm wondering what should I do to get at least 27mbps++ on wifi .... rather lazy to change the wifi router.

here's my pics :

wifi router and modem (nothing changed since my 5mbps --> 10mbps --> 30mbps) :


On LAN cable :


On wifi :

now scouting for affordable wifi router ... any suggestions?

This post has been edited by mmohdnor: Feb 4 2016, 10:13 AM