Solved ASUS RT-AX86U network performance issues

[samitro]

OK, reading all your posts again, here is the summary

1. PC - Modem: OK
2. Transfer between PCs LANs or LAN - LAN: OK
3. PC connected through router WIFI -> WAN -> Modem: OK
4. PC connected through router LAN - WAN - Modem: slow

Point 1 tells it is not an issue with the modem & internet
Point 2 tells it is not an issue on the PC's NIC & cable
Point 3 & 4 tell that there is a bottleneck routing traffic between LAN and WAN interfaces, but not between WIFI and WAN interfaces.

So it is either a hardware fault (impacting multiple units) or there is some kind of QoS / bandwidth limit per LAN port to avoid eating the whole bandwidth. Just guessing here. btw. Just came across this thread that was sent by another user here, does not seem to be an isolated issue

Solved - Wired speeds slow with three different ASUS WiFi 6 routers, any fixes?

If you have another router or can borrow a switch, I'd put the switch between your PC and router LAN port. Or between your modem and router WAN port. Disable DHCP on the router that you are using as switch first. I've seen some routers just not get along with some Ethernet devices that work...

www.snbforums.com

 

[TehNext]

Docsis 3.1, router (arris TG 3492/VM hub 4) in modem mode connected to the AX86U's 2.5 WAN.

Out of interest what, cables are using?

 

[Sanek2k6]

I have tried Shielded Cat 5E, Unshielded Cat 5E and Unshielded Cat 6 - pretty much the only stuff I have around the house. Connection from Modem to Router WAN is using Shielded Cat 5E, connection to my main PC is Cat 6. Using same Cat 6 cable connected over a USB 3.0 Ethernet adapter, there are no issues.

I messed a lot with my Main PC's Ethernet advanced settings and was able to squeeze out as much performance as I could - the biggest factor was me increasing the receive buffer of the adapter to 2048 from the default setting of 256 (doubled performance):

Also tried disabling all of the "offloading" features and none showed any improvement.

I would think it might be a QOS issue with the router of some kind, but again - work laptop has no issues! Very frustrating since this "improved number" is still well shy of what the laptop is seeing. I might connect the old router tomorrow and see if I still max out the connection with it, so maybe AX routers just have some compatibility issues with some hardware.

It did get me thinking that maybe its some Windows setting and my work laptop is preset to the corporate/IT-configured settings, so maybe something there differs from the defaults that makes it work well. I thought maybe it was the TCP Receive Window Auto-Tuning Level setting in Windows causing this, but disabling it didn't have any positive effect (work laptop has it set to normal as well). These are the TCP Windows settings on my main PC thats having issues.

 

[shabby]

I have the exact same issue with my ac86u. I noticed after a factory reset im getting the full 700mbps from my ISP but once I turn on ai protection it drops to 600mbps, turn on qos down to 500mps, turn on some other logging features and I'm down to 400mbps. But only on wired, wireless is peaking at 700mbps.
Try reseting the router back to stock and don't turn anything on.

 

[Sanek2k6]

I have the exact same issue with my ac86u. I noticed after a factory reset im getting the full 700mbps from my ISP but once I turn on ai protection it drops to 600mbps, turn on qos down to 500mps, turn on some other logging features and I'm down to 400mbps. But only on wired, wireless is peaking at 700mbps.
Try reseting the router back to stock and don't turn anything on.

Have not tried with this one, but I reset the previous RT-AX86U that had the same issue multiple times and I don’t use any of those advanced features.

 

[Sanek2k6]

OK, I decided to experiment a bit more, so ordered some shielded Cat7 cables on Amazon, as well as a 2.5g PCI-E network card with some good reviews and even a USBC Ethernet adapter (my video card has a pretty fast USBC port). Most of these things are future-proof and just good to have, plus not that expensive overall.

We’ll see if any of this makes any difference - obviously I should not need to do any of that, but I was curious, plus I hope to get more eyes on this thread, so we can hopefully get to the bottom of this eventually.

Was thinking about contacting ASUS again, but last time they just wanted me to send them the router, presuming it was faulty hardware, so not sure how much good that would do.

 

[KevTech]

Practical speeds of around 700Mbps is about all you will see on a USB adapter.

 

[Sanek2k6]

Practical speeds of around 700Mbps is about all you will see on a USB adapter.

This speed test is using my integrated Intel ethernet - its the best I could manage to get now after optimizing various things (mostly the receive buffer). In the past, none of these optimizations were necessary:

However this speed test was on my work laptop (Dell XPS 15) using the USB 3.0 Ethernet Adapter:

Using the USB 3.0 Ethernet adapter on my personal laptop yielded about 300 Mbps and I think I can get around 300-400 Mbps on my PC with it.

 

[tallytr]

Just bought AX86U a week ago, curious my wired Internet speed. I am able to reach over 900 Mbps on the Rogers 1G Internet plan. Also similar result by using my son laptop with WIFI 6 AX201, which indicates 2400 Mbps connect. FYI, latest firmware manually update, use most default setting, QOS is off, use 160 Mhz on 5G.
View attachment 27326

I am getting the same (Shaw 1G plan) but on my Wifi 5 router, RT-AC86U, had the RT-AX86U but returned it, didn't see the improvement to be honest, only at really short range did I see the link speed of my notebook really high up but no real world improvement...

 

[1ceLaz0r]

New firmware dropped last week, but i'm happy with my stability, so I'm not gonna chance being a guinea pig again

RT-AX86 Series(RT-AX86U/RT-AX86S)

ASUS gaming routers provide the very best gaming experience, with an arsenal of features and tools designed to improve online gaming performance and give you the competitive edge you need to win.

www.asus.com

 

[Sanek2k6]

Changed out cables to Cat7 shielded ones - no change. Tried using a USB-C Ethernet Adapter, but the performance was terrible (~150Mbit), even on the Dell (I think its just a bad adapter). Then I installed the new 2.5G Ethernet card (Realtek RTL8125 chip) I bought and the speeds appear to be normal now, at least up to the WAN speed limit):

(this is with some other stuff running on the network).

I have no idea if I'm actually getting 2.5G speeds out of that router (Link Speed is 2.5G), since I dont have anything to benchmark it. Plugging in a USB 3.0 SSD enclosure into one of the router's USB 3.0 ports only got me to ~100 MB/s for a few seconds, which then dropped to 30 MB/s, followed by 19 MB/s - I think maybe the router was throttling the CPU at that point. So I think its probably still not great as a NAS even with a more powerful CPU.

The memory was almost maxed out for some reason too btw. I guess if I get a decent NAS in the future and setup link aggregation, I'll be able to test it at 2G speeds, but not doing that any time soon.

Not sure why the router wasn't happy with my old Intel adapter, but at least the Realtek one seems to be working normally. The other PC I used for testing used an even older Intel adapter.

 

[SoCalReviews]

Strange incompatibilities can happen between different hardware but what's good is that you kept trying and finally found a solution that works. Congrats!

 

[pulp]

That's awesome news, Sanek2k6, congratulations on getting the fix after all your hard work!

This one should work just as well, eh? It's ASUS too. LOL

ASUS (PCE-C2500) 2.5G Base-T PCIe Network Adapter with backward compatibility. Supporting 2.5G/1G/100Mbps, RJ45 Port
Brand: ASUS
$84.99

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[nanochip]

I’ve noticed slow WAN upload speeds (over WiFi) using the 2.5 gbps port of the ax86u.

I have a gig connection (up/down) and if I use the 2.5 gbps port as the WAN interface (I have a switch upstream from the router), upload speeds are hard limited to 1/10 of the total capacity.

But if I use another 1gbps port as the WAN interface, I get the full gig. So it’s a problem with the router. Funny thing is, using the 2.5 gbps port for LAN transfers, I get the full speed. Something weird is happening.

 

[Sanek2k6]

Hopefully ASUS can keep pumping out the firmware updates because I do think it definitely needs them. The SMB share performance was definitely very poor - starting out at 100MB was good, but it was using 100% CPU on 2 of 4 cores (the other 2 were around 0%) and RAM was just about maxed (very close to 100%), which quickly fell all the way down to 19 MB/s... yeah I dont expect much from a router acting as a NAS, but it does have a 1.8GHz quad-core processor, so I think there is definitely some optimization there they can do. Was it throttling? Within a minute? Doubtful, unless the cooling is just insufficient, so no idea what went wrong.

 

[wardie]

Hopefully ASUS can keep pumping out the firmware updates because I do think it definitely needs them. The SMB share performance was definitely very poor - starting out at 100MB was good, but it was using 100% CPU on 2 of 4 cores (the other 2 were around 0%) and RAM was just about maxed (very close to 100%), which quickly fell all the way down to 19 MB/s... yeah I dont expect much from a router acting as a NAS, but it does have a 1.8GHz quad-core processor, so I think there is definitely some optimization there they can do. Was it throttling? Within a minute? Doubtful, unless the cooling is just insufficient, so no idea what went wrong.

Yeah I tried my 5300 with a USB disk and just watched the CPU and memory max out with some basic big transfers, resulting in a rapid loss of transfer speed. At the end of the day, it’s a router not a NAS so I use it as such. Have to say though my very old Apple AirPort Extreme never had such issues with USB disk (although without the internals transparency to be fair).

 

[Murat Y]

Hello. We are faced with the same situation. I connected the 2 TB portable disk to the router. your disk is 4/3 full. that it took a long time to read. When reading the disk, only 24mb of ram is left. As if there was no 4 core processor and 1 GB ram.then 128GB USB 3.0 I connected a flash disk. I set the 2 MP Samsung snv 6084 ip camera for recording to nas. moreover the recording type is mjpeg. Even in this case, all 4 cores were used extensively. also the free RAM is only 24 MB. frankly, a complete regret. because even the r6400 I bricked was working much more efficiently than ax86 with 800mhz dual CPU and 256 MB of ram. Again, the dsl ac68u I used in the previous years was not using so many resources in 2tb disk usage. Although the is 1 ghz dual cpu and 256 mb ram. As friend said, of course I don't expect a nas performance. but it shouldn't be that bad either.

 

[jsz]

I am getting the same (Shaw 1G plan) but on my Wifi 5 router, RT-AC86U, had the RT-AX86U but returned it, didn't see the improvement to be honest, only at really short range did I see the link speed of my notebook really high up but no real world improvement...

Same boat as me, except I'm on Spectrum 1G in the US. The only improvement I saw was close range and if I'm being honest, I feel like AX86U was worse at distance when it came to local interference and walls.

The AX86U has faster ramp up time when running speed test and I would assume this is due to the 1.5GHz processors in the Radio SoC.. The AC86U/GT-AC2900 has 800mhz radio processors in comparison. (I think this is the case for all wave 2 radios, at least from BCM and QCA).

I had the option of returning my GT-AC2900 at the time.. but there was an 80 USD difference and i figure I can upgrade to to 6E earlier if theres significant real world benefits.

Plan on running the GT-AC2900 for a couple years then going from there. Very stable router so far, but I'm 100% convinced that "wave 2 AX" hardware will be more complete down the road if revisions are made.

 

[SoCalReviews]

Same boat as me, except I'm on Spectrum 1G in the US. The only improvement I saw was close range and if I'm being honest, I feel like AX86U was worse at distance when it came to local interference and walls.

The AX86U has faster ramp up time when running speed test and I would assume this is due to the 1.5GHz processors in the Radio SoC.. The AC86U/GT-AC2900 has 800mhz radio processors in comparison. (I think this is the case for all wave 2 radios, at least from BCM and QCA).

I had the option of returning my GT-AC2900 at the time.. but there was an 80 USD difference and i figure I can upgrade to to 6E earlier if theres significant real worlThd benefits.

Plan on running the GT-AC2900 for a couple years then going from there. Very stable router so far, but I'm 100% convinced that "wave 2 AX" hardware will be more complete down the road if revisions are made.

I've been surprised to read some of the "meh" comments regarding the AX86U's Wifi performance compared to previous Asus routers. After upgrading from the RT-AC68P and RT-AC1900P I saw a dramatic improvement in wireless range on both 2.4Ghz and 5Ghz. Rooms on the other side of my home where I was experiencing intermittent drops are now rock solid and have very good throughput.

I also tested the AX86U range by walking down the street using my smart phone equipped with wireless AC and the Wifi Analyzer app and that was impressive too. The original RT-N66U on original firmware was the best 2.4Ghz range I ever tested... getting signal up to half a block away. The RT-AX86U range doesn't go that far but it's the best 2.4Ghz I've seen since the N66U and the 5Ghz signal is quite a lot better than the N66U and the AC68P/AC1900P series I owned.

However the most impressive thing about the AX86U was the dramatically noticeable improvement in decreased latency. Several reviews like CNET measured the lowest latency of any router they ever tested... https://www.cnet.com/news/asus-rt-ax86u-wi-fi-6-router-review/ "the RT-AX86U is just flat-out fantastic at handling latency, and easily the best router I've ever tested when it comes to lag."

For online gamers this is a huge advantage. If you aren't into online gaming maybe it's not such a big deal but when you consider the time and money online gamers invest in their setups that extra cost for having an ultra low latency wireless router like the AX86U is well worth it. Needless to say I am also an online gamer and I am not hiding the fact that I have become a huge fan of the RT-AX86U.

 

[L&LD]

RMerlin already hinted at that and is why I want one to be the main router over the RT-AX88U I have now.