Horrible wireless speeds with AC66U on Merlin 376.49_4

[c2881977@trbvm.com]

Hi all, I recently got this router and flashed Merlin's firmware on it but I've been having really bad wireless problems with it. My connection is 300 down and 20 up. Connected via ethernet I get those advertised speeds without much issue. However, I am unable to achieve anywhere close to those speeds on wireless, on both the 2.4 GHz channel and 5 GHz channel.

I've experienced extremely severe speed degredation with distance. Here are some download numbers to give you perspective:

Ethernet:
300 mbps (as expected)

Literally standing next to the router:
5 GHz - 50 mbps
2.4 GHz - 37 mbps

15 feet from the router:
5 GHz - 20 mbps
2.4 GHz - 10 mbps

30 feet from the router:
5 GHz - 10 mbps
2.4 GHz - <1 mbps

I have tried different devices, different combinations of wireless channels and bandwidths, and different modes, but they all yield the same result. Here are my settings:

2.4 GHz
Wireless mode: N only
Channel bandwidth: 20 MHz
Control channel: 7 (I have verified via the site survey that no other networks are on, or even near, this channel)
Security: WPA2-Personal AES

5 GHz
Wireless mode: N/AC mixed
Channel bandwidth: 20 MHz
Control channel: 149 (I have verified via the site survey that no other networks are on, or even near, this channel)
Security: WPA2-Personal AES

Any and all suggestions are welcome. Thank you all.

 

[N66uASUS]

Use older firmware. That helped me for n66u

 

[ika]

Don't know the cause ,but I just read it an other thread that using the built in site survey might mess up your wifi signal and requires a restart to get it fixed. I don't know if that's true or not, just trying to help. You could also try this fork. Good luck.

ps: Did you clear the nvram before you flashed Merlin's fw?

 

[c2881977@trbvm.com]

Which older firmware works well for you? Yeah, I cleared nvram after the flash. I actually switched from DD-WRT because for whatever reason DD-WRT was capping my download speeds at 100 mbps.

 

[RogerSC]

I assume that you have WMM (under "Wireless" -> "Professional") enabled? It needs to be enabled for fastest wireless speed.

Also, this isn't what your problem is, but if you want wireless-AC on 5GHz band, your should use a channel width that allows 80MHz. channel width. Or for faster wireless-N, you should use 40MHz. channel width on 5GHz. Using 20MHz. channel width is a good idea to limit interference on 2.4GHz. band, though, as you have that now. Generally speaking, interference with/from neighbors wireless networks isn't an issue on 5GHz. band.

Don't know if you've tried a reset to factory defaults, and then manually re-entering your configuration settings, but with problems like these I would first reset the router to factory defaults. Then reflash the current firmware. Then reset the router to factory settings again, and re-enter my settings manually. Just doing this may normalize the behavior of your router.

 

[System Error Message]

the practical bandwidth of wifi is 1/3 of theoratical rated. It looks like you are only utilising wireless N.

check your signal data rates from your test device too and make sure there arent interference from power lines.

 

[ColinTaylor]

I assume that you have WMM (under "Wireless" -> "Professional") enabled? It needs to be enabled for fastest wireless speed.

What has WMM got to do with wireless speed? As I understand it WMM only applies to QOS and/or power saving. This doesn't appear to be a contention issue.

 

[RussellInCincinnati]

What has WMM got to do with wireless speed? As I understand it WMM only applies to QOS and/or power saving. This doesn't appear to be a contention issue.

WMM totally DOES relate to max connection speeds, it's just not an obvious relationship. See KEL-L's more specific comment below. Besides am scratching my head trying to figure out arguments against setting it. There's a reason that Merlin firmware defaults to WMM on.

Struggled with getting nice 5 gigahertz connections between a slightly bulky EdiMax EW-7822UAC USB adapter and AC66U and AC68U Merlin routers. Until I stumbled upon:
-set router for N/AC only, client to AC only
-WMM enabled on client and router
-router control channel 161 (big improvement for some reason), but extension channel auto
-bandwidth 20/40/80 mhz
-of course AES encryption and WiFi password
-had to fold CLOSED the antenna of the EW-7822UAC adapter when it was TOO CLOSE to the WiFi router. This was not an obvious thing to do, it just turns out that the EdiMax 7822 can have too much of a good thing, signal-wise at very close link ranges.
-had to use the simpler drivers on the CD shipped with the EdiMax adapters to get the best link stability. The later drivers dated 2014 April or later were not helpful, despite having tons more interesting-sounding configuration features in the Windows properties for the adapters.

...after which am getting file copies at 215 megabits per second and 867mHz nominal link rates. Connection is a two-stream 5ghz AC link to the $30 dollar EdiMax adapter, but 80 megahertz bandwidth.

Am also getting a solid 433mhz nominal link and 170 megabits/second copy speeds with the little single-stream $18 dollar EdiMax EW-7811UTC USB adapter and Windows 8.1 client.

 

[Deleted member 22229]

If you disable WMM then your router will revert back to G specs and the max speed will be 54 mbps in real world speeds that means about 20mbps max. WMM needs to stay enabled.

 

[ColinTaylor]

If you disable WMM then your router will revert back to G specs and the max speed will be 54 mbps in real world speeds that means about 20mbps max. WMM needs to stay enabled.

Ah, I see.

I'm running an older version of the firmware and I don't see any option to turn WMM on or off. All I have under "Wireless - Professional" is "Enable WMM APSD" which presumably is something else.

UPDATE: To answer my own question... I tried turning off WMM APSD (on 2.4GHz) and it didn't effect the wireless link speed or throughput from my laptop. (Link speed was 144Mbps and throughput 77Mbps)

 

[noric]

I'm interested in this. I have an older firmware too (374.40), where there is no WMM settings, as ColinTaylor said. Is there a nvram setting to be edited via telnet?

 

[jerry6]

Well I'm getting great connection rate and transfer rates , connection rate 220 - 270 mbps , transfer rate 9- 11MBPS on 5 ghz band 30 feet away with 2 walls . This is with edimax 1200 AC client , get just about the same with Intel 5300 A N G client ,RT N-66 U , Merlin 376 -49-4 , so far no complaints .

 

[EdisonW]

Hi all,

I have an N66U, and starting with Merlin firmware's 376.48 (now on 376.49_4), my wireless performance has just TANKED...

On the third floor of my townhouse where previously my gear was easily getting 365Mbps connection rates to the router, I now barely get 145Mbps.

I've done complete factory resets (holding the WPS button for 20 seconds, then letting the router sit for 20 mins), and reloaded my settings from scratch (not using config backups), I still cannot get my performance back.

I don't think this has anything to do with Merlin, but rather something Asus has royally screwed up in the newest codebase for these routers.

If I move to the other end of my house where I was getting 217Mbps+ connection speeds, I'm now fortunate if I get something in the mid-50's, it's quite sad...

 

[tsunami2311]

Im getting 50+ mbit on both 2ghz/5ghz wireless from 20
feet away, 30 + feet is pushing it for this routers range hell that pushing it for most routers, surprised you even have connection

 

[Deleted member 22229]

Im getting 50+ mbit on both 2ghz/5ghz wireless from 20
feet away, 30 + feet is pushing it for this routers range hell that pushing it for most routers, surprised you even have connection

My home is 70' x 30' and i get full speeds across my whole house using 5Ghz using John's fork not even close with the 376 builds. Asus has gotten silly with this 80mw cap on output. I doubt John will be able to keep the fork going forever so my next router will likely be from a different manufacture.

 

[c2881977@trbvm.com]

WMM is enabled. I've tried different combinations of channels and channel bandwidths but nothing seems to help. Are there any other suggestions?

Also, I can try physically moving the router to a different location. Generally speaking, can doing this offer any significant benefit?

 

[mikecpt]

My home is 70' x 30' and i get full speeds across my whole house using 5Ghz using John's fork not even close with the 376 builds. Asus has gotten silly with this 80mw cap on output. I doubt John will be able to keep the fork going forever so my next router will likely be from a different manufacture.

I've notice the same issue with my RT-N66U, with John's fork In the point most far way from the router (this is about 15mts) I get a very low signal on 5Ghz a Slightly better on 2.4Ghz top speeds on the 15-20Mpbs range with several devices connected and streaming from my Plex Server to my chromecast (in this same room), just after the updates on merlin the chromecast doesn't even connect to the wifi, and my smartphone (One plus one) gets up to 1Mps tops... the difference is insane!

Could you kindly explain more about what Asus really changed or point me out to more info if there's any... ?

Maybe we could complain to them about this issue, seems to affect at least all RT-N66U users from what I see in the forums... It really feels like they just want to force us into buying the new models.... but this one is not exactly a old piece of junk... it still cost >100$ on Amazon, so I'm hoping they just didn't realise the mistake yet and will change whatever they made...

 

[cofetym]

Have you attempted any of the basic steps to reset your network?