RT-AC86U LAN speed limit at 200mbps (Runner & Flow cache enabled)

[Jasper Loo]

Firmware: 384.14_2
Model: RT-AC86U

Issues:
LAN speed is limit at 200mbps, but my WiFi speed can go up to 100% at 500mbps.
There's no NAT Acceleration setting, but HW acceleration shows:
Runner: Enabled - Flow Cache: Enabled

QoS Settings:
QoS Type: **Adaptive**
Queue Discipline: **sfq**

LAN-Switch Control:
Jumbo Frame: **Disable**
Spanning Tree Protocol: **Disable**

 

[ColinTaylor]

Disable QoS completely and test again. How are you testing the speed?

 

[Jasper Loo]

Disable QoS completely and test again. How are you testing the speed?

I tried disabling QoS completely but the speed is the same. 100~200mbps (speedtest.net)
My actual ISP bandwidth is 500mbps.

 

[Pak Kriss]

What's the result after a full factory reset without any specific setup/settings?

Sent from my SM-T805 using Asus RT-AC86U & Merlin 384.13

 

[Jasper Loo]

What's the result after a full factory reset without any specific setup/settings?

Sent from my SM-T805 using Asus RT-AC86U & Merlin 384.13

I do not plan to perform factory reset. I installed Merlin 384.14_2 on router first boot.

 

[Makaveli]

As part of the normal troubleshooting a factory reset maybe required since obviously something isn't working right.

 

[Smokindog]

And did you at least factory reset after installing Merlin?

 

[CaptainSTX]

I tried disabling QoS completely but the speed is the same. 100~200mbps (speedtest.net)
My actual ISP bandwidth is 500mbps.

You are never going to get 500 Mbps through a VPN tunnel. Even using a VPN appliance with a fast I7 processor or a PC I usually top out at 240 Mbps even when I had a gig connection. For the $5 you pay for a commercial VPN they can't or won't support really high speed connections. With your router you can expect the speed to top out in the low to mid 200s. VPN speeds are much more variable than your ISPs speed since you are really depending on two ISPs and congestion on both networks.

Also with you 500 Mbps line speed your router is already working just to push the data through add the VPN and you get what you get. Turning QOS off is the most important change you can make as it lightens the router's load. Changiing encryption from AES-256 to AES-128 might help if your provider supports it but in my experience it doesn't make much difference on an AC86.

 

[ColinTaylor]

@CaptainSTX VPN has never been mentioned in this thread. We can assume he isn't using one as he can get 500Mbps throughput with a WiFi client.

 

[Jasper Loo]

As part of the normal troubleshooting a factory reset maybe required since obviously something isn't working right.

ok, i will try factory reset. I haven't perform reset after installing merlin.
Btw, sorry posted this in official fw section.

 

[L&LD]

@Jasper Loo you may want to have a look at the M&M Config and the Nuclear Reset guide in my signature below to get your router to a good/known state.

 

[CaptainSTX]

@CaptainSTX VPN has never been mentioned in this thread. We can assume he isn't using one as he can get 500Mbps throughput with a WiFi client.

In rereading the string I thought he had mentioned VPN. In skimming it again I don't see VPN mentioned so that was me solving a problem he doesn't have.

 

[Jasper Loo]

@Jasper Loo you may want to have a look at the M&M Config and the Nuclear Reset guide in my signature below to get your router to a good/known state.

thanks!

 

[Jasper Loo]

Hi guys, I have performed factory reset but the problem still persist. LAN speed can only max out at 250mbps.

Any idea?

 

[maxbraketorque]

How are you testing speed? The more detail the better.

 

[Jasper Loo]

How are you testing speed? The more detail the better.

using speedtest.net.
My wifi on mobile can reach 500mbps.
My laptop with a USB 3.0 gigabit LAN to USB adapter can only reach 250mbps. (the same adapter reached 500mbps on my previous AC-88U)

 

[maxbraketorque]

My bet is some kind of hardware issue. Have you tried swapping ethernet cables? Do you have any switches in the path?

 

[Jasper Loo]

My bet is some kind of hardware issue. Have you tried swapping ethernet cables? Do you have any switches in the path?

Ok, i just tried it on another newer laptop, the speed is full 500mbps. I guess is the USB port bottleneck.
Thanks guys

 

[maxbraketorque]

Ok, i just tried it on another newer laptop, the speed is full 500mbps. I guess is the USB port bottleneck.
Thanks guys

If possible, try updating the USB ethernet driver.

 

[ajp2k14]

Ok, i just tried it on another newer laptop, the speed is full 500mbps. I guess is the USB port bottleneck.
Thanks guys

I hade the same problem with an USB3 Wifi-adapter. Make sure the USB adapter is running in USB3 mode and not USB2 with a tool like USBTreeView.