Asus AC88U poor WiFi speed

[Ricky]

I've been using Merlin's firmware on my router for a while now. I've always used either Ethernet or Powerline to connect to the router. I don't use my phone that much, so I rarely use WiFi nowadays. That said, I've got a new phone recently (Galaxy S8+) and I wanted to test the WiFi on the phone.

My internet plan is 200Mbps down and 20Mbps up. The only devices using up the ports on my router are just my laptop (connected via Powerline) and an Ethernet that connects my server to my router. My server has been turned off for several months now, as it is not in use. So there is only 1 port in use on the router. I get about 195Mbps down on either Ethernet or my Powerline.

I'm the only one living in the house, so there are no other users eating up bandwidth and affecting my speed tests. I always perform one test on one device at a time and I don't have any torrents or streaming or downloading going on in the background.

Now, onto the WiFi tests. I ran a couple of Speedtests on 2.4Ghz SSID and they all average 90~100 Mbps down and 20 Mbps up. Also ran speedtests with the 5Ghz SSID (I normally disable this radio, but enabled it only for this test) and the result is more or less the same. I've tested standing directly in front of the router (maybe 10cm away), as well as from a few rooms away. Result is the same. This isn't right, as I used to get 136Mbps back when I was still using a Galaxy S6. Router hasn't changed.

FYI, all Speedtests (either Ethernet, Powerline or WiFi) are all connected to the same server in the same region.

Here are the my router settings:

I've tried changing the Preamble from Short to Long, tried enabling legacy wireless mode with TX bursting (I know this doesn't make much sense, as this only applies to legacy wifi protocols/devices, but I've tested it anyway), and pretty much played around with all the settings found in the screenshot above.

I'm getting full signal bars on my phone and on my laptop. Laptop signal reports 144Mbps (2.4Ghz), but actual Speedtest is around 90Mbps. Phone reports 192Mbps (2.4Ghz) and 702Mbps (5Ghz), but actual is as mentioned above, 90~100Mbps for both bands.

If I test my phone from a few rooms away, the router's Wireless log reports my phone's -dbm at around -65 to -72. If I move my phone closer to the router, the -dbm drops to e.g. -50dbm. I have other devices around the house that sit closer to the router - a couple of Belkin Wemo Switches and a security IP camera. They are reporting the correct -dbm range (around -50 to -60). So it doesn't seem like the signal is the issue here.

I've also tried to adjust the antenna positions, but I doubt that made any difference as signal isn't an issue here. Furthermore, I've tested directly in front of the router, so that's as good of a signal as you can get. I did remove the antennas and installed them again. I've made sure they are installed correctly, not loose or anything like that.

I've also tried disabling my Firewall (including IPv6, although I don't have any IPv6 connections). No luck.

Disabled QOS, no luck either.

Finally, I've tried flashing the latest Asus firmware and my WiFi speed on the phone is the same, no change. Here's what I've done:

1. On Merlin, restore factory settings.
2. Powered off router and unplugged for 1 minute.
3. Plugged power back in and flashed official ASUS firmware.
4. Restore factory defaults on Asus firmware.
5. Setup basic WiFi settings (just WPA2-Personal with a password and that's it) and did a few speedtests (again, using the same Speedtest server).

Then I've reverted back to Merlin, pretty much the same steps as above:
1. On official Asus firmware, restore factory settings.
2. Powered off router and unplugged for 1 minute.
3. Plugged power back and flashed Merlin firmware.
4. Restore factory defaults on Merlin.
5. Setup basic WiFi settings and test. Same result. Then did a restore of my router config/settings.
6. Did another test, including Ethernet/Powerline. Same result as before - Ethernet/Powerline gets around 190~195Mbps down and WiFi still at max 100Mbps.

After flashing Merlin back, I did notice in the System log, it said something about:
"Dead loop on virtual device vlan10, fix it urgently!"

I haven't seen this message before and this message showed up twice at different times. Did a quick search online and people recommend telnet to the router and input the following:
"tc qdisc add dev vlan10 root pfifo"

So I've done that, but router says "File already exists".

People also recommend disabling AI Protection (which is enabled, as I've restored my router config). I intend to keep using this feature, so didn't really want to disable it. So I rebooted the router from the GUI and checked the logs again. This time, the message doesn't come up. To be sure, I power cycled the router and my ONT (router's WAN connects to my ONT) and message still hasn't come up. So hopefully this is all good now.

I thought the above might be related to my WiFi, so I've done a few more WiFi tests afterwards. No change.

I've had this router for more than 6 months and there hasn't been any new equipment added or changes made to my home, other than my new phone.

Would appreciate if someone could provide some suggestions/advice etc.

 

[tsunami2311]

maybe you have wifi interference now that wasn't there before, is there any new electronics they are near the router ?

 

[Ricky]

Nothing has changed. Nothing new has been added.

No one is using the microwave when I'm running the tests. Even if there is interference, standing directly 10cm in front of the router should at least see speed improvements compared to being 1~2 rooms away. However, the result is the same no matter where my phone is. The max I get is 100Mbps down and average is about 90~100Mbps.

I'm not on half duplex or anything like that, but it's as if the router's wifi is.

The signal strength is excellent/very strong and I've tried changing channels from 1, 6 and 11. Used inSSIDer and don't see any other networks interfering with mine.

 

[System Error Message]

change your channel to a middle channels on 5Ghz. Look at your available 5Ghz channels, calculate based on channel width and pick one that allows the entire width to cover the channel selection.
on 2.4Ghz, dont expect performance as this is very crowded with many things you cant see. Any wireless device nowadays uses 2.4Ghz even when though it doesnt say wifi N on the box. Broadcom's 4 channel 2.4Ghz is a scam because very few chips support it and it requires a non crowded 2.4Ghz environment (impossible) not to mention use in a country that allows using the channels (1,5,9,13) so for 2.4Ghz stick with the 20/40Mhz channel width or expect to see bad performance.
100Mb/s is very very good on 2.4Ghz. Practical 2.4Ghz speeds usually give about 50Mb/s wireless N at 20Mhz width. How are you expecting to get 200Mb/s on a 150Mb/s link? Practical wifi speeds for 2.4Ghz is 30% of rated link, 60% of rated link on 5Ghz.

The AC88U or AC3100 with its MU MIMO isnt actually meant for performance like the AC3200 or 5300, this is meant for a better spread of bandwidth across multiple devices.

If your wired link gets 200Mb/s then you just need to configure your wifi right as i said. My wifi settings allow for really good performance but they arent the settings people normally input as i set it for both performance and battery life optimising each band separately for what they're good at.

 

[Ricky]

change your channel to a middle channels on 5Ghz. Look at your available 5Ghz channels, calculate based on channel width and pick one that allows the entire width to cover the channel selection.
on 2.4Ghz, dont expect performance as this is very crowded with many things you cant see. Any wireless device nowadays uses 2.4Ghz even when though it doesnt say wifi N on the box. Broadcom's 4 channel 2.4Ghz is a scam because very few chips support it and it requires a non crowded 2.4Ghz environment (impossible) not to mention use in a country that allows using the channels (1,5,9,13) so for 2.4Ghz stick with the 20/40Mhz channel width or expect to see bad performance.
100Mb/s is very very good on 2.4Ghz. Practical 2.4Ghz speeds usually give about 50Mb/s wireless N at 20Mhz width. How are you expecting to get 200Mb/s on a 150Mb/s link? Practical wifi speeds for 2.4Ghz is 30% of rated link, 60% of rated link on 5Ghz.

I thought you're not supposed to use 20/40Mhz on 2.4Ghz, as 40Mhz is just terrible and out of all the researched articles I have found. Here's the setting I'm using for 5Ghz and using inSSIDer, no other networks overlaps my 5Ghz channel:

Just like I have done for 2.4Ghz, I have played around with the settings above and it did not change the result.

I'm not expecting 2.4Ghz to go near my rated speed of 200Mb/s. I know that 2.4Ghz is just for signal strength and 5Ghz is for performance. But based on what I was getting in the past on my devices, I know that my S6 could get around 130Mbps on 2.4Ghz no problem and that was testing in front of the router. I'm looking at the SpeedTest result history and there are at least 10 tests I've done averaging 130Mbps. I know for a fact that my sister's iPhone 6S was able to get around 130Mbps down as well, because I borrowed her phone several times in the past to carry out some of those tests.

Now, none of my wireless devices get anywhere near that speed, regardless if I'm using 2.4Ghz of 5Ghz and whether I'm standing directly in front or not. I don't think this is an interference issue and changing channels problem wouldn't matter here. I've tested 10 cm away from the router, I can literally touch it and I could rest my phone on top.

 

[System Error Message]

I thought you're not supposed to use 20/40Mhz on 2.4Ghz, as 40Mhz is just terrible and out of all the researched articles I have found. Here's the setting I'm using for 5Ghz and using inSSIDer, no other networks overlaps my 5Ghz channel:

I'm not expecting 2.4Ghz to go near my rated speed of 200Mb/s. I know that 2.4Ghz is just for signal strength and 5Ghz is for performance. But based on what I was getting in the past on my devices, I know that my S6 could get around 130Mbps on 2.4Ghz no problem and that was testing in front of the router. I'm looking at the SpeedTest result history and there are at least 10 tests I've done averaging 130Mbps. I know for a fact that my sister's iPhone 6S was able to get around 130Mbps down as well, because I borrowed her phone several times in the past to carry out some of those tests.

Now, none of my wireless devices get anywhere near that speed, regardless if I'm using 2.4Ghz of 5Ghz and whether I'm standing directly in front or not. I don't think this is an interference issue and changing channels problem wouldn't matter here. I've tested 10 cm away from the router, I can literally touch it and I could rest my phone on top.

Yes 40Mhz doesnt always work well on 2.4Ghz, but setting it to 20/40Mhz allows it to use 40Mhz when relevant giving you better speeds.
However the 5Ghz is what you need to tweak so i'll give you a list of settings.
set channel width to auto/multi. I set mine to the max but pick a middle channel (i.e. if there are 42,46,50,54 i would pick 46 or 50 for 80Mhz.
set protected manged frames to capable/allow (not required and not disabled)
set the multicast rate to max
set beacon interval to 50 (better battery)
set DTIM to 50 (better performance)
enable tx bursting
enable wmm no acknowledegement
enable optimise ampdu aggregration
play with the modulation scheme
Disable regulation (not region, but the 802.11 d+h)

Also dont test your speed with phones as phones use low power mode by default (you need a seperate app like wifi performance to force the phone to use wifi in non power save mode for better performance). So test it with a laptop instead.

 

[Ricky]

Yes 40Mhz doesnt always work well on 2.4Ghz, but setting it to 20/40Mhz allows it to use 40Mhz when relevant giving you better speeds.
However the 5Ghz is what you need to tweak so i'll give you a list of settings.
set channel width to auto/multi. I set mine to the max but pick a middle channel (i.e. if there are 42,46,50,54 i would pick 46 or 50 for 80Mhz.
set protected manged frames to capable/allow (not required and not disabled)
set the multicast rate to max
set beacon interval to 50 (better battery)
set DTIM to 50 (better performance)
enable tx bursting
enable wmm no acknowledegement
enable optimise ampdu aggregration
play with the modulation scheme
Disable regulation (not region, but the 802.11 d+h)

Also dont test your speed with phones as phones use low power mode by default (you need a seperate app like wifi performance to force the phone to use wifi in non power save mode for better performance). So test it with a laptop instead.

Thanks, I'll give that a try next time. I think I might have fixed the issue. I've done another factory reset on Merlin, power cycled longer this time, restored my config and did another test. My Galaxy S8+ is still getting max 100Mbps~105Mbps on 5Ghz and that's testing directly in front of the router. However, my laptop was able to get 193Mbps on 5Ghz and it has been consistent as I have done this 3 times in a row. All 3 tests were performed from my room, which is 2~3 rooms away from the router. My laptop is getting 4/5 signal strength bars and reporting about 520Mbps in the connection details.

Here's the graph on SpeedTest, it's staying at 190Mbps + consistently:

I'm not really too sure what's going on. I would've expected my S8+ to get higher than 100Mbps, especially comparing to the 130Mbps I was getting on my S6. While I'm a bit happier to see that my laptop is getting the proper speed, I don't really care about it since I always use a Powerline on my laptop. I'm more concerned about the devices that rely soley on wifi, despite that I don't have any performance related issues for any of them, just that I want to see them getting the expected wifi speed.

I'm a bit scared to play around with the settings, as I have somehow got one working properly and want it to stay that way. I'll monitor and see how things go I guess.

 

[System Error Message]

Thanks, I'll give that a try next time. I think I might have fixed the issue. I've done another factory reset on Merlin, power cycled longer this time, restored my config and did another test. My Galaxy S8+ is still getting max 100Mbps~105Mbps on 5Ghz and that's testing directly in front of the router. However, my laptop was able to get 193Mbps on 5Ghz and it has been consistent as I have done this 3 times in a row. All 3 tests were performed from my room, which is 2~3 rooms away from the router. My laptop is getting 4/5 signal strength bars and reporting about 520Mbps in the connection details.

Here's the graph on SpeedTest, it's staying at 190Mbps + consistently:

View attachment 10825

I'm not really too sure what's going on. I would've expected my S8+ to get higher than 100Mbps, especially comparing to the 130Mbps I was getting on my S6. While I'm a bit happier to see that my laptop is getting the proper speed, I don't really care about it since I always use a Powerline on my laptop. I'm more concerned about the devices that rely soley on wifi, despite that I don't have any performance related issues for any of them, just that I want to see them getting the expected wifi speed.

I'm a bit scared to play around with the settings, as I have somehow got one working properly and want it to stay that way. I'll monitor and see how things go I guess.

on phones, by default the wireless chip is in power save mode so you dont get much performance on the phone and pings are 70ms or more for LAN.

 

[Vexira]

Yes 40Mhz doesnt always work well on 2.4Ghz, but setting it to 20/40Mhz allows it to use 40Mhz when relevant giving you better speeds.
However the 5Ghz is what you need to tweak so i'll give you a list of settings.
set channel width to auto/multi. I set mine to the max but pick a middle channel (i.e. if there are 42,46,50,54 i would pick 46 or 50 for 80Mhz.
set protected manged frames to capable/allow (not required and not disabled)
set the multicast rate to max
set beacon interval to 50 (better battery)
set DTIM to 50 (better performance)
enable tx bursting
enable wmm no acknowledegement
enable optimise ampdu aggregration
play with the modulation scheme
Disable regulation (not region, but the 802.11 d+h)

Also dont test your speed with phones as phones use low power mode by default (you need a seperate app like wifi performance to force the phone to use wifi in non power save mode for better performance). So test it with a laptop instead.

isn't enable wmm no acknowledegement not good to enable?

 

[System Error Message]

isn't enable wmm no acknowledegement not good to enable?

nope, its good to enable because it allows wmm without acks which helps reduce traffic on wifi when transferring media.

https://routerguide.net/how-to-adjust-optimal-wmm-settings-improving-wireless-network-speed/

not to be offensive but many asians tend to be given the wrong advice and lessons for various things, especially on how to drive.

 

[Vexira]

not sure how disabling a crc is a good thing for general use but troubleshooting I guess so.
No-Acknowledgement
On (General Use), Off (High Wifi Interference Area)

No-Acknoledgement is an accuracy feature that improves the accuracy of the data transmitted. To make it work, the data stream is attached with error checking data to ensure the accuracy. You generally do not this option as long as you do not live in a compacted wifi neighborhood environment.

The easiest way to test it is to turn the No-Acknowledgement off, see if you run into any problems with your wireless connection. If there is no problem, you will then receive small amount of boost to your speed with No-Acknowledgement.
https://routerguide.net/how-to-adjust-optimal-wmm-settings-improving-wireless-network-speed/

 

[Vexira]

I'm just concerned about packet loss that's all

 

[Ricky]

OK, have just done another test on 5Ghz using my sister's iPhone 6S. Tested near the router, got 190Mbps down and 14Mbps up several times. Not sure why the upload sucks, but I don't really care about upload that much.

I guess my 5GHz is working correctly now, but 2.4Ghz speed still not as before. All devices are just getting 100Mbps max, at close range to router. Oh well, since I don't rely on WiFi most of the time and my devices are functioning and performing correctly, I guess I'm just gonna drop this one.

 

[tsunami2311]

OK, have just done another test on 5Ghz using my sister's iPhone 6S. Tested near the router, got 190Mbps down and 14Mbps up several times. Not sure why the upload sucks, but I don't really care about upload that much.

I guess my 5GHz is working correctly now, but 2.4Ghz speed still not as before. All devices are just getting 100Mbps max, at close range to router. Oh well, since I don't rely on WiFi most of the time and my devices are functioning and performing correctly, I guess I'm just gonna drop this one.

just cause you cant find the interference or think there isnt dont mean there isnt any. I have friend that cant even use 2.4ghz anywhere on her property and she leave near no one and i cant find any interference let alone what it coming from but it is there. could stand right next to router and have same effect ast 30+ feet away from it didnt work or was insanely slow and that is despite devices have 100% signal or 10%.

mean while 5ghz give same singal % but works perfectly fine. almost everything uses 2.4ghz at this point almost everything is wireless too just cause you didnt have interference before dont mean it cant happen.