First, are you connected using Wireless?

And if you are using Wireless, which wireless channel are you using?

Install the software called inSSIDer and check what are the least used channel in your area and configure your 841ND to use that channel.

I can assure you that is not the router issue, the router is working fine as how it is suppose to be. Someone could be hogging your internet connection or just chances are at that point of time u doing the speedtest the connection was slow.

I been on TPLink 841 for more then 7 months now. I never switched off the router from the day it came out of the box. IPTV is connected to it, my seedbox, network bluray media player, NAS server. Sometimes all of it is running at 1 go, and not forgetting my smartphone/tab and also 2 PC's are connected to it.

Here is the speedtest results. Take note that 100+ torrents are seeding in the background.