Question Asus RT-AC5300 hardwired bottleneck


Oct 4, 2018
I have an Asus AC-5300 router. It has 4 gigbit LAN ports and is tri band (2.4, 5, and 5).

I am hardwired directly from my PC to the router.

For some reason I am getting a bottleneck on the router. I have 1 gig internet speed (940 mb actual) but for some reason I am only getting about 450 mb when running a speed test.

When I hooked my computer directly to the modem, I got the full 940 mb download. My router's firmware is fully up to date. Yes I have rebooted all devices multiple times.

There is currently no other traffic on the router that would be hogging bandwidth.

Thank you for your assistance.


Mar 15, 2018
That is completely normal.
When you are on the speed test website, you can read, that you need to connect directly to the modem to get the correct speed.
It will be slower through routers because the router is sharing the bandwidth with other devices connected.

Remember that the speed is not really a "speed", it is actually a bandwidth, which converts to Mb per second average over time.

The router has the job to share this available bandwidth between connected devices.
If you have 3 devices connected to your router, you will get 940Mbps/3 = 313.3Mbps available for each device
Likewise with 2 devices: 940Mbps/2 = 470Mbps each device or 4 devices: 970Mbps/4 =242.5Mbps each device.

Its no mystery, just a question understanding the function of network "speed" or more correctly: bandwidth.

Hope this humble explanation makes you better understand whats going on ?
Factory reset the router and set only the admin password and wifi passwords.

Modern routers have a feature that lets the NAT traffic bypass the cpu and use a hardware accelerator. Without this feature the CPU must do all the NAT function and they are not fast enough and bottleneck the traffic.

Many features like firewall or Qos disable this bypass function and all the traffic will pass through the CPU. Even very simple features like traffic monitoring can cause the traffic to not be able to use the hardware acceleration feature.

Pretty much when you have a high speed internet connection you have to use your router as a very dumb box. Even the very fastest ones do not have the cpu power to do much. You would need a router with a actual pc type of cpu to keep up and do many functions.

You might try the merlin firmware image. I doubt it makes much difference but it is optimized a bit better.