Reduced Wan-Wired Lan performance.

[Awarbrick89]

Hello SNB Community!


My name is Aaron and I come to you today with a request for Final Opinions My RT-N66u has met all my needs. Its a great and powerful router.
However, I recently upgraded my internet to a 100Mbps plan, and it was then that I learnt that my Wired Lan speeds were delivering less than 50% of my potential bandwidth. I could only achieve a fastest result of 47Mbps when wired to the N66u.
Strangely enough however, I could still get ~90Mbps when testing Wirelessly.......

I connected my computer directly to my modem (bypassing the N66u) and I instantly achieved 95Mbps results in speedtests.

I tried my DIR-655 in place of the RT-N66u, and was able to achieve the proper full speeds on all devices.

Now,, I have tried different Firmwares and revisions, including Merlin and Tomato, I cleared the nvram every time even if it wasnt necessary JUST in case. Tested all cables. My modem is indicating a gigabit connection to my router, and my pc is confirming a gigabit connection to the router. So all is good on that front.

So after reading all that, is it safe to assume I have a hardware problem and I should RMA the N66u?

 

[kaiguy]

There are quite a few threads about the ability of this router to achieve full speeds on fast fiber connections. The common recommendation to maximize your speed seem to be to ensure that hardware acceleration is enabled (it will be disabled automatically if you use anything like QOS or parental controls).

 

[Awarbrick89]

There are multiple threads? huh I went through over 10 pages in the N66u forum and searched with google using about 50 different phrasings of my problem without finding a post that sounded similar to my situation...
Closest I could find was
http://forums.smallnetbuilder.com/showthread.php?t=10900
But his was only a 10Mbps loss and mine is over 50.....

Hardware Acceleration is enabled (and enabled by default I think) However Im still confused on how I can achieve 97mbps wirelessly (or when wired directly to the modem) but not through wired lan from the N66u?

Theres no way every person who owns this router is just 'dealing' with only getting 50Mbps max of whichever high speed internet plan when wired directly in

So my question remains, knowing that Ive tried everything,
Does it sound like a hardware fault and I should RMA?

 

[Awarbrick89]

And I COMPLETELY forgot, oddly enough, my speed when wired goes up to 55Mbps when I enable QoS.... Weird Huh?

 

[RMerlin]

I would look at your Ethernet cables first. Make sure they are all Cat5e or Cat6. Try replacing them just to be on the safe side in case you have a bad cable.

Make sure you don't have anything set with Jumbo Frames enabled (router and computers), as it will cause lots of trouble if not everyone on your network segment uses the same frame size.

 

[SoCalReviews]

If using better cabling (Cat5e, Cat6 or shielded Cat7 spec) doesn't help then this sounds to me like it still could be a settings issue. I would first make sure the Ethernet drivers on your wired devices are up to date. Make sure your router power adapter seems to be working ok (check the adapter lights, they should be lit solid).

Next, whether you have already or haven't done this I would write down your settings and do a 15 second hard reset (reset button) of the modem. Let it boot up so that it seems to be working. Then power cycle off for 30 seconds and back on. Then I would flash with the latest stock Asus 4.270 firmware. Make sure the router is working again. Do another 15 second hard reset of the router. Do basic configuration with stock settings. Make sure the router is working. Then power cycle the router for 30 seconds off and then back on again with the internet modem connected to the router. Power cycle the modem also if necessary. Then test the wired throughput speed again with stock settings and standard Asus firmware.

If you still have problems there might be another method you could try to reset the router's firmware settings another way but this simple method has always worked for me. Last year I had some strange speed related issues immediately after updating the firmware and going through this process once or twice seemed to get everything working perfectly again. I haven't had any issues after updating the firmware since that time. I use mostly the stock Asus settings except for the wireless radios where I run with 2.4Ghz using fixed channel and 20Mhz bandwidth for better reliability.

 

[Awarbrick89]

Thank you guys for your input!
Jumbo Frames are of course disabled
However.........

All The Cables are good. I know this to be true because i can get full speed when wired directly to the modem (and all i do is switch my pc ethernet plug from the router to the modem), and wireless devices get full speed regardless of setup.

And please dont ask me to reset it again lol Ive power cycled and reset and factory reset and cleared nvram soo many times I can hear the router sigh and curse now whenever I change something I have definitely run it as stock as possible throughout all of this as well.

Now, I just connected a pretty old Macbook directly to the N66u with a cable and it tested ~90Mbps...........

Soo..... If my PC can get full speed when connected directly to the modem then my card is obviously functional yes?
And if another computer (laptop in this case) can attain full speed when connected to the Router, then the router must be functioning properly too, correct?

So if this be the case, then, now should I assume theres an incompatibility between my Realtek ethernet controller thats on my Asus M5A99X Evo R2.0 motherboard and the Asus RT-N66u router switch? is that even possible?

 

[dkjay]

I'm seeing something very similar.

Just got my RT-N66U today. With the old router I'd get 55mbps down on a wired connection. With the new N66U I'm getting 20-24mbps down. Wireless however I can get up to 50+mbps.

I didn't do a speed test on stock firmware fresh out of the box. I immediately put on Merlins firmware 3.0.0.4.270.26b, noticed the issue and put stock firmware back on and still saw the same issue. Now I'm back to Merlin and have the issue still.

Any ideas? HW accelerator is enabled.

Thanks

 

[Awarbrick89]

Sorry to hear that dkjay!

I need to apologize I think

I tried many configurations with the wires except one.....
Attaching another computer to the same cable I use for my desktop.
I merely assumed that since the cable functioned on the Modem to my PC, that its failure when connected to the Router must've been the N66u's fault.

It seems that the laptop I previously wired to the Router gets the SAME speed as my desktop now! Under 50Mbps.....

So it is the cable after all, I'm not sure HOW its the cable, since it works just fine when connected to the modem. But I guess it is what it is!

Thank you all for your help

PS - dkjay - definitely try different cables in different configurations
Don't waste 40 hours of your life on an assumption like me

 

[RMerlin]

So it is the cable after all, I'm not sure HOW its the cable, since it works just fine when connected to the modem. But I guess it is what it is!

If your modem only has a 100 Mbits interface, it might be more stable then than when your desktop tries to connect at gigabit speed with the router's gigabit ports. That's why I never rule out cable issues until a person has actually physically tried a different cable.

 

[Awarbrick89]

If your modem only has a 100 Mbits interface, it might be more stable then than when your desktop tries to connect at gigabit speed with the router's gigabit ports. That's why I never rule out cable issues until a person has actually physically tried a different cable.

Well my modem is a gigabit Cisco Modem from Shaw. Definitely gigabit enabled since its capable of up to 250Mbps speeds.

The ~50ft cable I was using was made for me by a Shaw Installer. Writing on it states its a Cat.5e cable... So maybe he wired it wrong because with the shaw modem it works just fine but the router is not compatible somehow. Meh. So i have so go out and buy a cable. Could be worse

PS - Thank you Merlin. Its nice to know the gurus are out there helping the little people as it were

 

[dkjay]

Swapping cables hasn't helped me yet. I've tried several and get the same results (~20mbps down). On top of that the old router (RT-N16) worked just fine with the old cables (getting 50+mpbs down).

However, I was able to connect a different laptop and got 50+mbps on the second laptop using the same cables.

Does this point to a possible driver issue for the lan card in the original laptop? Any other ideas?

 

[iatacs19]

I have a 100/20 connection and I have no problems getting up to 125Mbps down and up to 40Mbps up via Ethernet or Wi-Fi on my RT-N66U. (I tested the download speed by downloading some large ISOs from MSDN and I get consistent 13MB/sec. with peaks at 15MB/sec) I am using CAT5e cabling all around and I have several switches in between the router and client PCs. I am running Merlin's Firmware Version: 3.0.0.4.270.26. Almost all my clients run intel NIC or Wi-Fi.

Check your cable modem to make sure it's bonding the channels. Usually you can check at 192.168.100.1 URL.

 

[dkjay]

A bit more food for thought, I put Tomato (Shibby) on the router and can get 55+ down with the same cables. Any idea why the Asus-based firmware only gives me 20-ish?

 

[Hothersale]

Is the computer's ethernet adapter is set to Full Duplex speed?

 

[dkjay]

Not really sure, how would I check (Windows 7)?

Would it matter since its at ~50mpbs with Tomato but only ~20 with Asus/Merlin firmware?

 

[Jameson6]

New Asus RT-N66U Owner

Hello SNB Community!


My name is Aaron and I come to you today with a request for Final Opinions My RT-N66u has met all my needs. Its a great and powerful router.
However, I recently upgraded my internet to a 100Mbps plan, and it was then that I learnt that my Wired Lan speeds were delivering less than 50% of my potential bandwidth. I could only achieve a fastest result of 47Mbps when wired to the N66u.
Strangely enough however, I could still get ~90Mbps when testing Wirelessly.......

I connected my computer directly to my modem (bypassing the N66u) and I instantly achieved 95Mbps results in speedtests.

I tried my DIR-655 in place of the RT-N66u, and was able to achieve the proper full speeds on all devices.

Now,, I have tried different Firmwares and revisions, including Merlin and Tomato, I cleared the nvram every time even if it wasnt necessary JUST in case. Tested all cables. My modem is indicating a gigabit connection to my router, and my pc is confirming a gigabit connection to the router. So all is good on that front.

So after reading all that, is it safe to assume I have a hardware problem and I should RMA the N66u?

Almost EXACTLY the same issue as OP.

Modem: Motorola SB6180
Router: RT N66U

Computer wired direct to modem get approx 100mbps/25mbps.

When plugging in the router it seems to cap out at approx 50%, starts strong then degrades to less then half when going direct to modem.

Confirmed NIC has latest drivers.
Confirmed the router had the latest firmware.
Power cycled multiple times in sequence (e.g. modem then router).
Performed a hard reset and cleared NVRAM.
Flashed Merlin's build (v. 3.0.0.4.260.21).
I have replaced rj45 cords with brand new cat6.
Flashed back to orginal firmware (v3.0.0.4.354).
Disabled Traffic Mgr, Parental Controls, jumbo frame, HW accelerator enabled.

Everytime I would change something I would test the speed against the modem then the modem/router, same results. At first it spikes at 50% then drops to about 30-40% when going direct to modem.

I'm almost at my wits end with this haha. Have read such rave reviews and was hoping to benefit from it. Any other suggestions??

 

[RMerlin]

I think I've seen a couple of people posting issues specific to Motorola cablemodems that went away once replaced. Not saying that is the same issue as either of you tho. Try doing a forum search for Motorola or your model number.

The first thing I would try is to turn off the modem for 10 minutes (just power cycling it is not enough, cablemodems need a longer downtime to fully close the existing connection at the ISP's end), then turn it back on. Quite a few persons fixed their performance issues this way.

Also make sure DOwnload Master is not installed or enabled.

 

[somms]

A bit more food for thought, I put Tomato (Shibby) on the router and can get 55+ down with the same cables. Any idea why the Asus-based firmware only gives me 20-ish?

http://forums.smallnetbuilder.com/showthread.php?p=68007#post68007

Shot in the dark here but a major difference between stock firmware and Shibby's is the lack of CTF. Wonder if this feature is affecting some with certain types of cable modems?

FWIW: I'm able to achieve the full 100Mb/s up/down throughput from my fiber provider using Shibby's firmware that lacks CTF...

 

[RMerlin]

Shot in the dark here but a major difference between stock firmware and Shibby's is the lack of CTF. Wonder if this feature is affecting some with certain types of cable modems?

FWIW: I'm able to achieve the full 100Mb/s up/down throughput from my fiber provider using Shibby's firmware that lacks CTF...

I did have one user who fixed his performance issues by actually disabling HW acceleration, so it's definitely worth a try.

CTF isn't needed for 100 Mbps connections.