Question Extremely slow speed on a very fast connection


Aug 1, 2014
I have comcast Xfinity 400Mbps. I am standing next to the modem/router that Comcast gave me and my cheap Android phone shows speed of 400Mbps. I walk in to my home office which is the next room behind the wall my cellphone shows 300Mbps. My desktop has a wireless adapter and speed test shows only 40Mbps

My pc is operating on Windows 10.

Specs of Linksys WUSB6300 shows max 864 Mbps so adapter is not the problem

Specs of my motherboard can be found here; Essentially it is Gigabit so motherboard is not the problem

Here is how adapter settings look

I am not seeing problems anywhere but then why am I getting so slow speed?
You will see the so encoding method on your screen shot show 173.3. This is not really the speed just like the 867 is not really a speed but this number should be 867

What the 173.3 means is you are only using 20mhz radio channels. To get 867 you need to run 80mhz.

Not real sure why this is something that is negotiated between the end device and the router. Most end devices you can not actually set the channel width but there are some you can. You could see if your router has a way to force it to run 80mhz channels.