AC3100 gigabit speeds

[NyCShadow]

Hi all,

I have an AC3100 which I purchased a couple days ago, I have noticed that the speeds are not anywhere near my gigabit connection with Xfinity comcast. When I first got it the speeds were great but then all of a sudden they are not surpassing over 150mb (weird thing is the upload is fine). http://speedtest.xfinity.com/results/J9965H58S5YPZ67

Thing's I've done so far are;

• Updated to merlin firmware 380.68 (same issue happens)

• Downgraded to stock firmware of 3.0.0.4.382.15852 (helped for a little then download speeds lowered again)

• Called ASUS support who advised me to use firmware Version 3.0.0.4.380.7743 (same thing, speeds were fine that night then in the morning speeds were slow again)

• Called ASUS for the second time and they told me to use Version 3.0.0.4.380.7266 (same story as the others)

When I have my computer plugged directly into the modem the speeds are at the consistent speeds I should be getting of at least 900mb down and upload is 40ish (upload doesnt seem to be affected in this issue)

I did find this old thread regarding a bug in the merlin firmware https://www.snbforums.com/threads/r...-lan-speed-slowdown-reproducible-video.36523/ (do you think this could've happened to my router)

I also tried this suggestion in this thread (https://www.snbforums.com/threads/turn-off-fa-and-not-ctf.36890/) which was the steps below. This was fine until I rebooted the router and then same problem.

copy and paste below

nvram set ctf_fa_cap=0
nvram commit
reboot

I am considering returning this and getting a 3rd AC3100 (first one the 5ghz wifi would drop and the wifi button was not responsive)

My modem I am using is an Arris Surfboard SB8200 3.1 DOSCIS

Any suggestions or input would be greatly appreciated.

 

[Trikein]

What are you speeds when wireless through the router? If those are faster then wired/ethernet, then the issue is specific to the ethernet interface. Can any device connect at the faster speeds when wired? If not, the first thing I try is enabling/disabling Hardware acceleration under LAN > Switch control. Also, see threads below for any possible conflict between Arris modems and Asus routers. Have you tried with any different model modems by any chance? That would rule some things out.

 

[Trikein]

Also looking at the post your mention, I assume you used the config. trick to allow HW acceleration and disable flow control. If so, this may be affected by firmware updates that change the config. The thread seems to mention that the traffic control feature of the router conflicts with flow control being off, but I won't go into that too much until you confirm disabling flow control was intentional. IMO it's better to have it on with QoS to decrease bufferbloat, even if it decrease maximum upload for the improvements in latency you get. YMMV.

 

[NyCShadow]

What are you speeds when wireless through the router? If those are faster then wired/ethernet, then the issue is specific to the ethernet interface. Can any device connect at the faster speeds when wired? If not, the first thing I try is enabling/disabling Hardware acceleration under LAN > Switch control. Also, see threads below for any possible conflict between Arris modems and Asus routers. Have you tried with any different model modems by any chance? That would rule some things out.

The speeds for wifi when this happens are very slow as well around 2mb down and the 40 upload is still consistent. The hardware acceleration is already on as that is on by default. And I verified that it was on just now as well. I did the command I mentioned when I telnet into the router which did not help. I'm currently running firmware 7627 from Asus website and it's working good since last night. I'm afraid to reboot the router and have it go bad again but I guess I need to do that to see if I need to return this thing if it continues to happen. Seems like the only thing that fixes it is a firmware load of a version I haven't used yet.

 

[Trikein]

A couple things I would suggest is if you have tried with HW acceleration on and flow control off, try the reverse, with HW accel. off and flow control on. Also check that you have fat packets enabled on both the router and the NIC properties. Make sure AIProtection and Parental Controls are disabled. Make sure adaptive QoS is disabled for both the upload and download and disable the bandwidth monitor entirely(for now). Basically go through all the router settings and look for any green "On" switch, ask yourself if you use/need the feature, and when in doubt, diable. Your trying to turn off as much stuff that could use up router resources, see what speed you get then, and then start turning things back on. Before you do any of that, you can save your settings and revert back for emergencies.

As for the hardware, make sure the computer shows the connection speed of 1000Mbps(Gigabit) when you right click on the local area connection and check it's status. Also make sure you are either using high quality CAT5e or CAT6/A if you have it, between both the modem and router and router and PC. Reboot into safe mode with networking, or disable any AntiVirus or any programs that might use a internet connection in your task tray. Also, if not in safe mode, make sure any browser add ons are disabled and the browser is up to date(ie Chrome). Finally, run a test from this site, and post the results. Sorry for the long post, but hopefully that will give enough data to show where the problem is. I would expect 600-700Mbps pretty easily, but anything beyond that will start depending on the hardware of your computer.

 

[NyCShadow]

I have tried all that you suggested and today the speeds went back to being slower than what I should be getting. It's just randomly doing it because I checked the uptime on the router and it did not reboot the last 3 days. It worked great all weekend until this morning, I know its not the modem because I plugged it straight to the PC and speeds are as expected. I even plugged in my old RT-AC66R and that gets about 500-600MB down (main reason I replaced it cause it wouldnt pull the full 1gigabit speed). Only other thing I can think of now is replacing this router once again with a 3rd one and hope for the best. I really dont want to change brands as I have used ASUS for years now and am very comfortable with it, I hesitate to get a Netgear cause of the horrible customer service I have heard about.

 

[Trikein]

Can you provide the data from the tests when it was slow?

 

[NyCShadow]

Hi Trikein,

Are you asking for the speed data?

 

[Trikein]

Yes, from the test and link I gave in bold in post #5.

 

[NyCShadow]

Yes, from the test and link I gave in bold in post #5.

http://www.dslreports.com/speedtest/24190354

Another one from xfinity speedtest

http://speedtest.xfinity.com/results/J9E9SRFT2XB5QO4

 

[Trikein]

Why did you run the test as fiber? Do you have Comcast Fiber or Comcast Gigabit via DOCSIS 3.1? Also, can you do a DSLR test direct to the modem/ONT to compare? You said in OP you were getting 900Mbps that way, so I want to compare the test result to what you just gave.

 

[NyCShadow]

Why did you run the test as fiber? Do you have Comcast Fiber or Comcast Gigabit via DOCSIS 3.1? Also, can you do a DSLR test direct to the modem/ONT to compare? You said in OP you were getting 900Mbps that way, so I want to compare the test result to what you just gave.

I have Comcast Gigabit via DOCSIS 3.1

Straight to modem test

http://www.dslreports.com/speedtest/24191869

Plugged into Router

http://www.dslreports.com/speedtest/24192263

 

[NyCShadow]

Rebooted the router several times and here are the results now, I dont think I should have to reboot the router multiple times in order to get the right results.

http://www.dslreports.com/speedtest/24193567

 

[Trikein]

Yea, i think you messed something up by trying the NVRAM trick. Anyone know how to revert it back? I assume factory reset doesn't. Also, did you make sure all QoS is disabled on the router? Last, what model ethernet NIC do you have in the PC and does it show a gigabit connection rate?

 

[NyCShadow]

Yea, i think you messed something up by trying the NVRAM trick. Anyone know how to revert it back? I assume factory reset doesn't. Also, did you make sure all QoS is disabled on the router? Last, what model ethernet NIC do you have in the PC and does it show a gigabit connection rate?

I would think putting in a 1 vs a 0 on the NVRAM thing would do the opposite? QOS is disabled and I have a gigabit connection rate on the PC, when the router puts out slow speeds I know its not just 1 PC cause I plug in another machine with a gig card and same speeds.

Here is my mobo with a gig NIC

https://www.asus.com/us/Motherboards/MAXIMUS-VIII-HERO/

ROG MAXIMUS VIII HERO LGA1151 DDR4 DP HDMI M.2 U.2 USB 3.1 Z170 ATX Motherboard

• 5-way Optimization with 1-click overclocking
• Reinvented SupremeFX 2015 Audio with top-to-bottom upgrades
• Best-in-class Intel® Gb LAN with GameFirst technology
• Customizable Aura RGB heatsink Lighting
• Dual U.2 + M.2 + SATA Express for uncompromising storage speeds

 

[Trikein]

Ahh, looks to use GameFirst. Here is another thread where it slowed down a Asus laptop. Disable that under windows services.

 

[NyCShadow]

Gamefirst is not installed

 

[Trikein]

I am not sure then. If it's not a feature issue it could be a hardware defect. Have you tried with a different router? Different PC?

 

[NyCShadow]

I am not sure then. If it's not a feature issue it could be a hardware defect. Have you tried with a different router? Different PC?

Yeah I have an AC66R and works just fine, other machines on the AC3100 same results when its not working right.

 

[Trikein]

The only other thing I can suggest is try disabling anything and everything you don't need in the router for a internet connection. Also look at the logs. If that doesn't do anything that the next step is contacting Asus for a RMA.