USB WiFI adapter seems to be bandwidth limited? Weird

Recently my download speed has diminished seriously. It used to be very high and now it is 4 MBps according to several Speedtest sites.

I have 4 computers in our home: wife's, TV room, my desktop and my laptop.

We have ATT Internet with 24 MBps download speed.

Two of these computers (my desktop and laptop) download at 4 MBps and the other two download at 29 MBps.

By swapping the Wifi adapters, the speed reduction follows the USB adapter.

I was not able to figure out why this just happened. I know I got very high speeds in the past, but lately things seemed to slow down.

I tried as many debugging steps as I could even full uninstalls and re-installs, but I could not get past about 4 or 5 MBps download.

I bought a new WiFi adapter for the desktop and the problem went away, but the laptop has a built-in Wifi on the motherboard. I guess I could still install a second one externally if I need it.

It is mysterious how two different WiFi adapters on two different computers will suddenly misbehave like this.

The WiFi that mis-performed was a Netgear WNA1100. I replaced it with an ASUS AC-56 - a nice dual-band USB 3 adapter.

The Wifi in the laptop is a Qualcomm Atheros AR956x device.

The device drivers were up-to-date and all our computers are at the same current version of Windows 10 Pro 64-bit (15063.413)

blaze007 said:

the speed of the adapter is limited by the speed of usb 2.0.

This is not the issue. I had previously experienced much higher than 5 MBps on the older adapter. All of the other adapters that get 29 MBPs are on USB 2 ports.

Berton said:

Based upon the model numbers it would appear the Netgear is 802.11b/g/n while the ASUS is the newer 802.11ac. To get the best performance the Router also needs to be AC compatible, I have recently acquired 2 computers with the AC adapter and next purchase will need to be an AC Router.

My ATT-supplied router is B/G/N with a 40 MHz bandwidth.

But I will repeat, I had much higher bandwidth in the recent past. But not after something happened, like, maybe, the Creator Update of Windows changed something.

I have had no hardware changes in many months.