Slow speedtest results on router compare to LAN clients

[JWoo]

I have the quad core RT-AX56U. I am paying for 600 Mbps down and 20 Mbps up Internet service. I have seen as high as 723 MB download measured from the router. As shown in the image, I just ran Speedtest from the Router using Merlin 386.4 and measured 702 MB download and 26 MB upload. Many ISPs over dimension to avoid subscriber complaints. When running Speedtest, the CPU load will jump up temporarily, mainly on Core 1. From my perspective, this function works great and is an accurate reflection. Most of the CPU load increase while running Speedtest on the router seems to be processes ookla, bcm_archer_us and bcmsw_rx. The quad core on the RT-AX56U seems to be a pretty robust CPU. I am NOT using TrendMicro AI Protection, which could be why Speedtest on the router works well for me.

 

[dlandiss]

measured 702 MB download

No, 702 MB would be over 5600 Mb. I suspect you meant 702 Mb.

 

[sivaprasath]

There is a another thread going on similar to this issue. Looks like the new release 386.4 is having some issue with speed test when compared with 386.3_2 releases.

RT-AC68U as AiMesh node cuts half LAN speed

Hi All. I have two devices AiMesh setup with stock firmware (upgraded to the latest version) - AX88U as the main router and AC68U as a node. There is wired connection between them. The device connected to the main router shows ~920 Mbits/sec in iperf3 test. The same device connected to the node...

www.snbforums.com

 

[ColinTaylor]

There is a another thread going on similar to this issue. Looks like the new release 386.4 is having some issue with speed test when compared with 386.3_2 releases.

RT-AC68U as AiMesh node cuts half LAN speed

Hi All. I have two devices AiMesh setup with stock firmware (upgraded to the latest version) - AX88U as the main router and AC68U as a node. There is wired connection between them. The device connected to the main router shows ~920 Mbits/sec in iperf3 test. The same device connected to the node...

www.snbforums.com

That is a completely different issue.

 

[Irishrow]

I believe that the

I think this is hardware limitation so there's nothing that can be done to "fix" it. Just ignore it and use a LAN speed test instead.

I believe Colin Taylor may be correct--that hardware is throttling the test. I have CenturyLink Gigabit (960 Mbps) service and the promise of a direct Speedtest to see the "true speed" of my service is tempting but unavailable. It CONSISTENTLY tops out on my RT-AC88U at around 350 Mbps up or down. Since I have an Asus PCE-AC88 AC-3100 Wireless PCI-E adapter, I run the Ookla speed test over Wi-Fi and watch it from the QoS Bandwidth Monitor Tab on the router. From there you can readily see the true throughput of all traffic even during the test.

 

[Viktor Jaep]

I believe Colin Taylor may be correct--that hardware is throttling the test.

That's because @ColinTaylor is correct. Running speedtests on this hardware is stretching resources and CPU capabilities in higher bandwidth scenarios. To get a true measure... plug your WAN cable directly into your x86 laptop and run a speed test from there.

 

[Irishrow]

That's because @ColinTaylor is correct. Running speedtests on this hardware is stretching resources and CPU capabilities in higher bandwidth scenarios. To get a true measure... plug your WAN cable directly into your x86 laptop and run a speed test from there.

Thank you for the spirited reply. My laptop network card is not capable of anything near 960 Mbps. So I use my desktop (up a floor) with the Wi-fi card as noted. While I'm very interested in checking my speed (CenturyLink regularly plops me 400 miles from Denver near Wichita, KS) I'm not curious enough to spend another $1,000 on it--I'm really more interested in the speed at my desktop. But if I ever am, I'll certainly take your advice.

 

[Viktor Jaep]

Thank you for the spirited reply. My laptop network card is not capable of anything near 960 Mbps. So I use my desktop (up a floor) with the Wi-fi card as noted. While I'm very interested in checking my speed (CenturyLink regularly plops me 400 miles from Denver near Wichita, KS) I'm not curious enough to spend another $1,000 on it--I'm really more interested in the speed at my desktop. But if I ever am, I'll certainly take your advice.

Absolutely! Most modern laptops/desktops should be able to support a 1Gb connection, that is if they have a LAN port anymore... But yeah, if you have the chance to hook up a physical x86 box to your incoming WAN cable coming directly off your modem, that's the purest source you can measure from. Good luck!

 

[Piggie]

Thank you for the spirited reply. My laptop network card is not capable of anything near 960 Mbps. So I use my desktop (up a floor) with the Wi-fi card as noted. While I'm very interested in checking my speed (CenturyLink regularly plops me 400 miles from Denver near Wichita, KS) I'm not curious enough to spend another $1,000 on it--I'm really more interested in the speed at my desktop. But if I ever am, I'll certainly take your advice.

I usually run internal speed test after a firmware update - or if I'm trying to trouble shoot a slow connection. My ax92u gives me accurate results if I turn off traffic analyzer, AI protect and qos. Also, some of the servers in Denver do not consistently get 1gbps. The Comcast server in Denver is usually the best test if you're looking for 1gbps. After I run the internal test, I turn AI protect, traffic analzyer and qos back on.

So, if you're looking for better results without upgrading, you may want to try testing by turning those functions off. You may see more accurate results.

 

[Viktor Jaep]

So, if you're looking for better results without upgrading, you may want to try testing by turning those functions off. You may see more accurate results.

Just for comparison's sake... on my AC86U, even with all these functions already turned off, I'm only seeing about 1/3 of the speed being reported compared to it's actual bandwidth. ie. I'm seeing around 350-400Mb, when it should be closer to 1Gb.

 

[Piggie]

Just for comparison's sake... on my AC86U, even with all these functions already turned off, I'm only seeing about 1/3 of the speed being reported compared to it's actual bandwidth. ie. I'm seeing around 350-400Mb, when it should be closer to 1Gb.

I made a correction on my previous post - it's Traffic Analyzer that needs to be off -- not traffic monitor. I believe both the AX92u and AC86u have the same Broadcom BCM 4906, 1.8 GHz processor. If I run internal test with those on, my speeds are around 300-400 mbps off. Are you running open VPN? You may try switching that off, too.

 

[Tech9]

I believe both the AX92u and AC86u have the same Broadcom BCM 4906, 1.8 GHz processor.

Correct. It's the scripts @Viktor Jaep runs on his router. In identical configuration the speed test will show identical results.

 

[Viktor Jaep]

If you want to tinker with your router - Asuswrt-Merlin

It's because I choose this.

 

[Tech9]

It's because I choose this.

You understand I would give different advice to different people, right? I read the other posts/threads too.

 

[vincentcan]

I made a correction on my previous post - it's Traffic Analyzer that needs to be off -- not traffic monitor. I believe both the AX92u and AC86u have the same Broadcom BCM 4906, 1.8 GHz processor. If I run internal test with those on, my speeds are around 300-400 mbps off. Are you running open VPN? You may try switching that off, too.

I confirm what Piggie advised.
I disabled traffic analyzer, AI protect and qos... and bingo !!
I was stuck around 700Mbps and after disabling the seeting, 1700 Mbps (even more than advised by my ISP).
Thanks again !!