T4U supports 5GHz channel 36~48 and 52~64.
Can you change a proper channel on the main router for a try?

Vivian wrote

T4U supports 5GHz channel 36~48 and 52~64.
Can you change a proper channel on the main router for a try?

Hi Vivian,

Thank you for your reply and clarifying the channels available for the T4U. I was able to connect when I set the channel of the router to 44, but I am only getting 3mbps download, and 100mbps upload speed on speedtest. When I right click on the wireless connection and click status however, I am seeing 500mbps as the connection speed.

Do you have an idea on what else I can tweak to improve this connection? Below are the hardware involved and what I have tried.

Speedtest on LAN connection: ~900mbps
Speedtest on 2Ghz wireless: ~100mbps
Router: D-link-850L
Adapter: Archer T4U driver Driver version: 1024.6.1016.2013

I've tried switching channels but no success. I am still getting abysmal download speeds on 5Ghz. Moving the pc close to the router does not have an effect either. :(

Thanks again!

I just joined this forum as I am having similar issues with the T4U adaptor, I am connected at 5Ghz 802.11ac and even when the tplink software reports my signal as 100% my connection rate never exceeds 390Mbps.

I to also downloaded the latest driver

Archer T4U_V1_150602



Published Date

02/06/15

and yet windows reports it as T4U driver Driver version: 1024.6.1016.2013 14/11/2013

when looking at the .inf for that driver it says
;; netrtwlanu.inf
;;
;; Realtek Wireless 802.11b/g/n USB 2.0 Network Adapter
;;
;; Copyright (C) 2012 Realtek Semiconductor Corp.
;;
;; This release is primarily for WHQL test.
;;

personally i'm going to look into what chipset the T4U uses and try and get a driver from the manufacturer as clearly there is a problem with the current release, that being it's 2 years old.