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RT-AC68U - very slow 2.4G wireless (Merlin)

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OzTrip

Occasional Visitor
Hi guys,

The router is RT-AC86U (not able to change thread title)

Here are my settings:

5G - Channel 20/40/80, Control Channel Auto - Max Speed 92 Mbps
2.4G - Channel 40, Control Channel Auto - Max Speed 3 Mbps

I disabled USB 3.0 & WPS as I read somewhere this can cause some issues everything else I left Merlin stock.

Tested on the same device in the same place. The issue is with any device connected to 2.4G.
I don't use "Smart Connect" as I discovered this issue while using smart connect.

Any ideas what can cause this issue?
 
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What firmware are you using? What are your ISP speeds? What scripts are you running? Are you using QoS? Are you using a VPN? Are you using new SSID's, at least as a test (use the Guest network to test new SSID's)?

What device are you using to test? What is the test method? Have you used a different browser to test with? What anti-virus program are you running? Have you updated the drivers to the latest available? Have you changed any of the default driver settings? Have you 'forgotten' the network settings, rebooted the device, and then re-associated to the router again and then test?

How far away is the router to your test device?

Have you tried a fixed control channel (for both bands)?

When was the last time you did a full M&M Config (please see link in my signature below for details)?
 
What firmware are you using? What are your ISP speeds? What scripts are you running? Are you using QoS? Are you using a VPN? Are you using new SSID's, at least as a test (use the Guest network to test new SSID's)?

What device are you using to test? What is the test method? Have you used a different browser to test with? What anti-virus program are you running? Have you updated the drivers to the latest available? Have you changed any of the default driver settings? Have you 'forgotten' the network settings, rebooted the device, and then re-associated to the router again and then test?

How far away is the router to your test device?

Have you tried a fixed control channel (for both bands)?

When was the last time you did a full M&M Config (please see link in my signature below for details)?

What firmware are you using? - Merlin 384.16 (latest)
What are your ISP speeds? - 90 Mbps
What scripts are you running? - none
Are you using QoS? yes/no tried both
Are you using a VPN? - yes but only for a dedicated device (other)
Are you using new SSID's - Yes I tried guest 2.4G with the same issue
What device are you using to test? - iPad, iPhone, MacBook Pro
What is the test method? - Speedtest app or web
Have you used a different browser to test with? - Yes all 5 browsers
What anti-virus program are you running? - phone test, none
Have you updated the drivers to the latest available? - Yes all the latest
Have you changed any of the default driver settings? - no
Have you 'forgotten' the network settings, rebooted the device, and then re-associated to the router again and then test? - no, I'm going to try this now
 
Have you 'forgotten' the network settings, rebooted the device, and then re-associated to the router again and then test? - yes, no improvements

More tests (2-bed apartment):

1m away from the router

5G - iPhone, Speedtest 92 Mbps
2.4G - iPhone, Speedtest 30 Mbps

Around 10m away from the router and 2 walls

5G - iPhone, Speedtest 84 Mbps
2.4G - iPhone, Speedtest 1-2 Mbps
 
Did it ever work? Is this the replacement 86U?

OE
 
Did it ever work? Is this the replacement 86U?

OE

Yes, I replaced RT-AC68U with RT-AC86U. Here is my floor plan with all speeds measured on the latest iPad Pro (Speedtest.net). Strangely enough, 5G performs here better in the longer distance than the 2G?

 
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I'm on RT-AC68U, Merlin v386.3_2.

I'm here because my 2.4 is slow too. I can't find a solution anywhere. Googling for possible solutions links to several articles all mention distance between the devices, channel, signal noise, etc.

I hard reset the router. Everything at its default.

--5 GHz band (80 MHz) has speedtest results at 200~250mbps.
--2.4 GHz band (20 MHz, 'N' only) speedtest results are at 30~50mbps.

Tested with iPhone in my hand and the router on the floor near my feet.
 
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--2.4 GHz band (20 MHz, 'N' only) speedtest results are at 30~50mbps.

Speed 30-50Mbps on 2.4GHz is good. Usually 2.4GHz band is busy, hard to get maximum possible speeds. 1-stream N client maximum link speed is 72Mbps, 2-stream clients get 144Mbps. The expected throughput is about half of the link speed. Your router works as expected. All you can do is play with different Wi-Fi channels and find one with more available bandwidth. I can get up to 90Mbps in my house with more quiet Wi-Fi environment, but no more than 40Mbps in my downtown apartment with 20+ 2.4GHz networks around.
 
1m away from the router

5G - iPhone, Speedtest 92 Mbps
2.4G - iPhone, Speedtest 30 Mbps
As tech9 said 30-50Mbps is what is expected for 2.4Ghz. Maybe you have some interference between the router and the bedroom, 10 meters shouldn't make that big of a difference. Can you try a different location?
Anecdotally, I've disabled the 2.4Ghz on my 86U because it became a nuisance with frequent disconnects. The last Merlin FW that 2.4ghz worked well for me with no major problems was 384.18.
 
Speed 30-50Mbps on 2.4GHz is good.
It is? Then what is 802.11n's 300mbps about? I'm trying speedtest on a fresh reset of my router, default settings, no other devices connected. The iPhone and router are 5 feet apart.
 
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It is? Then what is 802.11n's 300mbps about? I'm trying speedtest on a fresh rest of my router, default settings, no other devices connected. The iPhone and router are 5 feet apart.
With the right client in the right location under the right conditions then way more than 300Mbps is possible. It's just that for most of us the combination of devices, obstructions and other networks will make what is attainable far lower!

*For a long while the only reason for me using AiMesh was a single device that connected at very low speeds in a part of the house. When that one device was retired, it became apparent that its replacement could manage far greater speeds even without the use of the AiMesh node.

**On some devices turning off Bluetooth can greatly increase 2.4GHz WiFi speeds!
 
Then what is 802.11n's 300mbps about?

N300 is the marketing term for 2-stream N devices. 300Mbps is the maximum link speed @40MHz wide channel in ideal conditions. In theory it can reach 200Mbps throughput, if you live in the middle of a cornfield with no other WI-Fi networks around. Real world performance is much lower.
 
N300 is the marketing term for 2-stream N devices. 300Mbps is the maximum link speed @40MHz wide channel in ideal conditions. In theory it can reach 200Mbps throughput, if you live in the middle of a cornfield with no other WI-Fi networks around. Real world performance is much lower.
Is the interference truly that dramatic? Like...even when the router is next to the WiFi device I won't see the theoretical speedtests?

Isn't 40 MHz on 2.4 taboo (for lack of a better exaggeration)?
 
Available bandwidth on 2.4GHz is low. We have 11x 20MHz channels only in most countries. This is the highway, your router is one car in the traffic. 100km/h speed may be allowed, but not possible most of the time. You are close to the router, but the router sees the other traffic on the highway and has to wait for a gap. 40MHz channel is like hauling an oversized load that takes 6 lanes on a busy highway, slowing everyone further down.
 
Then what is 802.11n's 300mbps about?

You might want to Google these things and read up how WiFi works. There are tons of explanation on the Internet.

OE
 

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