802.11 AC Real World Speed Disappointment - Asus RT-AC3200

[rossi]

I made an account to see if anyone has any ideas since you guys seem to be pretty knowledgeable. I expect to get about half of the reported link rates and I am not able to achieve anything above 200 Mbps using Lan Test, iperf, or wget transfers.

I recently upgraded my main router hardware to the Asus RT AC3200. I'm using my old RT AC66U as a media bridge. I am getting very disappointing wireless speeds between the two Asus AC devices (really all my devices but to simplify the testing I figured this media bridge is the best to analyze and compare). Here are the details:

Both routers are on the 2/3/2017 version of Asus Merlin firmware with mostly default wireless settings. The Media bridge is connected to the 5GHz-2 channel 149 / 80 Mghz band of the AC3200. The AC66U is reporting a link rate of 1300 Mbps and RSSI of -40 dBm. Should be good right? What would guys expect as a real life Mbps?

I haven't setup Download Master on the routers to try iperf, but I am testing with wget directly on the router hardware to eliminate any other machine thin pipe issues. My test consists of downloading a video file on a local web server.

I SSH directly into the AC66U and download a test video file hosted on a web server on my LAN:
wget 192.168.0.61/21.avi -O /dev/null
=> 12.0MB/s in 56s

Downloading the same file through an SSH terminal on my wired NAS:
wget 192.168.0.61/21.avi -O /dev/null
=> 81.1MB/s in 9.3s

So what gives? The link speed and connection are reporting fantastic numbers. Why can't I seem to realize their potential? Is AC just this slow, or this there a magic setting I am missing? Is there some way to make use of the 160Mhz channel bandwidth of the AC3200?

Thanks for taking the time to help. Totally stunned and disappointed by my AC devices and really hope one of you experts can provide some insight.

 

[rossi]

I posted the wget test since that seemed the simplest, but I've found it is flawed since it is bound by the CPU on the router. My low bandwidth wireless issue still persists though.

On a 6ft Cat6 cable connected to the media bridge AC66U router I max out at 110Mbps according to iperf 2.0.5, my NAS running that iperf version can get 930Mbps on a wire.

I've tried many of the toggles on the professional tab without any luck. Disabling beamforming reduces the speed by ~10Mbps but thats the only option which caused a noticeable effect.

 

[pete y testing]

ok so lets have a look at the reality of wifi and what it is capable of in real world conditions

with a 3 x 3 wifi client connecting to a 3 x 3 wireless router and syncing somewhere close to 1300M ( btw this would have to be pretty close and in most cases in the same room ) the average max throughput you could expect doing a single large file transfer is about 55 to 60 MB/s and i have tested that using an asus rt-ac68u and an asus pce-ac68 client adapter with a synology nas

so first of get a 3 x 3 wireless client to test the 3200 out on its own

in my testing the asus rt-ac3200 and asus pce-ac68 was a bit slower at around 50MB/s but still way faster than your result

so you have to first look at the 3200 and see if its causing the slow rate , then if it isnt move on to the 66u

i suspect its the 66u causing the issue as even if the 66u media bridge was losing 50% you would still be seeing better speeds than you are

also make sure qos isnt causing the issue by disabling on both units if possible

 

[rossi]

Yeah that's not a bad idea. The devices I have tested straight to the AC3200 are my old HP laptop and my Nexus 6P. The laptop has N only and a max rate of 300Mbps. It gets 150Mbps on iperf which is expected. My phone is AC with a BCM4358 and supposedly can get 866, but I can only get around 200Mbps on it. Not sure if this is my phone's fault or the router's.

My office PC has a PCE-AC68 which is 3x3. Unfortunately it is too far away from the router (which is why the media bridge). Maybe I'll take the time to move the tower this week to the middle of the living room and report back the results. It will be a good sanity check to verify the router is putting out the speed. Good to hear you are getting around 50MB. I have an expectation now which will motivate me to move my machine temporarily.

qos is disabled and HW acceleration is enabled on both.

 

[pete y testing]

I have an expectation now which will motivate me to move my machine temporarily.

might be easier for testing if you bring the mountain to mohamid so to speak and just bring the router over to the desktop and do some quick throughput tests

 

[MichaelCG]

Something is for sure up with the setup....Using a pair of RT-N66U, I am able to run around the 200Mbps speed across the media bridge using two wired systems. From the info you have provided, I would assume there is a signal quality issue causing the speeds to be less than impressive.

 

[rossi]

OK I setup a super simple test. PC -> RT-AC3200 <- Laptop. The Laptop was connected to the router with a small Cat 6. An iperf3 server was run on the PC and the client was run on the Laptop.

Test 1 - PC connected with Cat6 cable into the AC3200:
iperf3 ~901 Mbps

Test 2 - PC connected to 5GHz-2 band 149 / 80 Mhz. Wireless log lists 1300 / 526 Mbps -24 dBm. The antenna are basically touching. I disabled the 2.4 and the 5-1 bands on the professional tab and enabled mac address filtering to block all my other devices from connecting. Network map only shows my PC.
iperf3 ~270Mbps

What am I missing here? Is this really the top end speed I should be getting? Is my router faulty?

Some additional information....
-Laptop had much slower speeds as host with wire so went with server on the PC
-Updated the drivers on my PC's PCE-AC68 to the latest before trying
-With PC wired my Nexus 6P running iperf3 as client could only get ~197Mbps
-With PC wired my Nexus 9 running iperf3 as client could get ~271Mbps
-Tried the 5Ghz-1 band and got ~260Mbps
-Tried without the mac filtering and got same results
-I tried Lan Test as well which gave similar results, but iperf gave faster wired speeds and I can run it on android
-CPU usage on the AC3200 never went above 16%

 

[rossi]

Haha, I disconnected my little test and hooked everything back up and now my media bridge (AC3200 - AC66U) is also providing speeds of ~270Mbps. At the very least this is a great lesson to fully unplug the router after making configuration changes. No idea which configuration change needed a power cycle... but yeah...

With your guys suggestion I was able to increase my speed :-D. Still not getting 50MB/s though. Still disappointed with the maximum speeds this "3200" can achieve.

 

[Samir]

That's a lot of trouble for 270Mbps. Moca 2.0 starts at 300Mbps.

 

[MichaelCG]

Based on the link speed (1300/526) you reported from the wireless logs, 270Mbps sounds about right (real world ~50% of link). I would continue to play with antenna placement and channel selection to see if you can get that link speed to increase. I don't own enough AC gear myself to know what the real world limits are for AC.

As for Moca at 300Mbps....isn't that just the link speed? Pretty sure my Moca devices are linked at 600Mbps and I am lucky to get 20-30Mbps. Moca has similar challenges as WiFi....unclean signal tanks the speeds.

 

[Samir]

As for Moca at 300Mbps....isn't that just the link speed? Pretty sure my Moca devices are linked at 600Mbps and I am lucky to get 20-30Mbps. Moca has similar challenges as WiFi....unclean signal tanks the speeds.

Nope, no games with the bandwidth on Moca like there is on wifi and powerline. In just another thread, there's iperfs showing 800Mbps between two systems.

Unclean signal can even tank ethernet, but known specification wires between two endpoints beats waves through the air or over power circuits--and I've used both on our networks.

 

[MichaelCG]

Good point...I am mixing up MOCA vs PowerLine....ignore my comments.

 

[Samir]

Good point...I am mixing up MOCA vs PowerLine....ignore my comments.

All good! It's hard to keep it all straight these days.

 

[gowg]

I briefly tested a Velop with a AC66U as a media bridge and I got a somewhat reliable 650 mbps file transfer, but I had to have it within 10ft, right above the Velop upstairs. I live a crowded building in the city, so even the 5GHz spectrum is fairly clogged, I'm now on netgear powerline 1200. I might have to try MOCA if it's that good! It took me half an hour just to squeeze out 165 mbps from ideal outlets.

 

[Samir]

I've had really great luck with powerline adapters, even just 500av ones. But it seems moca 2.0 takes the reliability of a good powerline connection to the next level. I have one location in which I'm going to try a Moca 2.0 when I get a chance. It should up the bandwidth by 10x from what we're getting over powerline, which would be very impressive.