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Router speed drop solved

2006-01-22 (updated: 2014-08-17) by
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I've been lurking here for a while trying to solve my speed problem. Thanks to everyone for all the great tips, but I had to laugh when I finally figured this one out. Maybe someone else can use the tip:

I just got upgraded to Comcast 6Mbs, but was only getting throughputs in the 2-3Mbs range, with an occasional 4.5Mbs, and an occasional 1Mbs. Really frustrating. I tried all the tweaks here. TCPOptimizer is an awesome little program, and seemed to make some marginal, but inconsistent improvement. I got rid of ZoneAlarm since v5 seemed to cause a problem even though I had v6. No software firewall, and new software firewall: same problem. No antivirus software, and new AV software: same problem.

I have a Linksys BEFCMU10 (the original version) cable modem, and my main router is a Netgear WGR614 v1 wireless router. The wireless is turned on and used, but not for this connection. All the connections are wired Ethernet. Lot's of posters here have newer versions of those things, but my same problem. I considered buying new equipment, but it turns out that even this old stuff works perfectly, as you will see.

Going straight from the modem, I get full 6Mbs+. Through the router, it drops by half or more. During testing, I was cycling things on and off, switching the wiring when I finally stumbled on the problem. I was connected directly through the modem, but had the router turned on, and my speed dropped by half! I figured I had the wiring wrong or something, but nope, no part of my system was connect to the router. I have a homemade wood rack, and the router sits just above the modem. I could do a Speakeasy test wired through the modem getting 6Mbs, and watch the speed drop as I powered up the router.

So, the problem is: electrical noise! All the cables are shielded, and the power cords are segregated from the data cables, so the noise is coming directly from the devices. And low and behold, when I separated the router and modem by a few slots on my rack, I'm getting full speed minus about 10%, which is probably reasonable for router overhead and marginal residual noise. I imagine a lot of you out there have your router sitting on top of or below your modem. It's a stupidly simple solution (although it took me a week to stumble on it): if your having line speed problems, try separating your router and modem.

Hope this tip helps someone out there. And thanks for everyone else's help.

  User Reviews/Comments:
by Anonymous - 2006-02-06 04:15
by anonymous - 2006-02-14 14:31
didn't work for me :( but i'm wirelessly connected
by katiehashimero - 2006-03-15 13:42
i would had never in a decade stumble onto that.
i need to try this now afta i do this reply.
i am not wireless i use a linksys also with a Acatel homespeed modem at 6mbs also. at recent upgrade i notice millasecond shortburst of highspeed trimming down to ave 350+ kbs, and sometime trim down more.
if this works i will be pleased as i also have tried the tweaks but have not down registry treaking yet by hand.
I have win xp home sp2 linksys router and Not wireless.
i welcome anymore suggestions also.
nice goin.
London UK
by katiehashimero - 2006-03-18 12:50
i tried the moving modems and routers apart.
did'nt do anything different speedwise.
i need to know exactly what to do in the tweaks to get my 6mbs.
i am payin for it and i want to get it.
I use XP home linksys router and modem is from the IP provider.
where do i need to edit what to edit what patches to use?
i need to get some tips out there.
i awaite in- patiently.
by anonymous - 2006-03-24 12:31
Try Cat 5e or cat 6 cables, upgrade your NIC to 10/100/1000. Might work, it did for me.
by anonymous - 2006-04-08 08:45
Thanks for the tip. I was also stumped by a slower than expected ADSL speed and, after reading your article, seperated my (under-insulated) phone line from some power cables. It ended up improving my downstream speed by about 50%.
by sugar - 2006-11-16 23:26
Gosh, THANKS~!!!! I wondered why RoadRunner was not as fast as it was supposed to be. I finally decided to do a speed rating and it was 2750 or thereabout. Over 5 after I Separated the modem and router.

NEVER would have thought of it !!!!

by Stile7 - 2006-11-20 23:52
You are the MAN!!!!! I stumbled across your discussion here from a Google search. I've been having the same sluggish problems with my Linksys BEFCMU10. I disconnected the SMC wireless router altogether but still slow connection. So on seeing your advice, I moved the modem 1 foot further away from the power stip which sits right behind it. My speed went from 600Kbps to 3.7Mbps! I am once again whole, birds are singing, young children are skipping through fields of poppies and all is right with the world.

Many Many thanks again.
by anonymous - 2006-11-23 00:48
Great Tip. I Was searching through MTU and other enhancements but this got the job done. I have a Wireless Broadband Modem (Enters Home Wirelessly) hooked up to Wireless router(Wifi) (Belkin). They were right next to each other in center of the home. Modem had strong signal and was fast but not fast enough. I moved the Wireless modem and Router Apart 2.5 feet and boom! Nearly doubled my rated speed. Could have been two fold since interference would affect the net comming in and my Wireless Network Both. Great Tip.

My ISP = Clearwire
by flash2000 - 2007-04-29 16:09
Hey guys, I wanted to let you know that I was having the same issue with my linksys wireless g router.

My service (road runner cable through Time Warner) offers speeds up to 10 megs down and 1 meg up (RR Turbo)

When I connected to the linksys router directly with Ethernet, I could pull about 8.5 megs down from

But when I connected through wireless, it cut the speed in half, around 4 megs a second.

I tried everything from calling the techs at Road Runner, to chatting with the linksys tech support. Everything they told me to do didn't help.

Then I sent to dslreports and clicked on TOOLS and did a tweak test. It told me I needed to change my RWIN settings. I downloaded a simple program, changed my RWIN settings, rebooted and like magic I was getting the same pull (8 megs down) from my wireless as I was when I connected by ethernet.

So, if you're having issues with wireless running slower than ethernet, and it doesn't have to do with channel or location interference, then try this RWIN settings change. Fixed everything right up for me.
by Prakash MP - 2007-05-24 20:39
In my case I removed the DSL FIlter and the download speed doubled
by seeyoujimmy - 2007-08-26 07:12
Don't forget Cordless phones can also jam a wireless router, don't plug a cordless phone into the same line filter feeding a router :(
by anonymous - 2007-08-26 14:49
I have found flourescent bulbs and ballasts will cause problems with your network also. Incandescents will cause problems, but to a much lesser degree. A technician at Earthlink told me to make an aluminum foil tent and place it over my modem. As strange as it looked it actually worked.

by Franimal - 2007-09-03 06:32
This is a fantastic tip!! Unfortunately, I have a modem router so it's impossible to separate the two :( I've also lost 25% of my connection speed since buying this modem/router, which is a tad annoying!! My old modem gave me just under 4Mbps download speed, the new (LinkSys) only gives me 2.9Mbps. However, I still have the old modem, and only need the router when my son needs to connect to the network so I can use the modem most of the time. When I have enough money, I'll get a separate router and take it from there :)

Nice going on finding the problem though! Would never have thought of that!
by Surrey - 2008-04-04 19:42
I have a cable modem through a wireless router.

Wireless ok but nowhere near as good as wired connection.

Moved router away from modem (about 2 feet) and now there is hardly any difference.
Great tip. Thanks
by alanfreeman - 2008-06-15 13:44
I will try this seems simple enough. I,too, tried everything else!
by jaypitsby - 2008-08-06 09:13
Brilliant! Had same problem (and same hardware). Worked like a charm. This is why God invented geeks.
by anonymous - 2008-10-29 01:54
many thanks!!!
by anonymous - 2008-12-02 10:08
Thank you VERY much for this article! Even though it's a bit dated, it is 100% relevant today, maybe even more so with higher speeds! My router and modem were already separated by about 4 feet, so I didn't think this article's issue was my issue. However, my (wired) router was sitting atop a TV in my bedroom. You guessed it - after I moved my router away from the TVI've nearly tripled my average download speed (and I even switched from wired to wireless!) Thank you, thank you, thank you.
by anonymous - 2009-02-04 13:11
I called Comcast yesterday to complain about speed issues, I was about at 30mb/sec when connected directly into the modem and .1 when not. I bought a new router last night, same results, I then separated the stupid pieces of equipment and boom full speeds. go figure
by anonymous - 2009-02-04 14:32
Stumbled onto this article. This is great. Just fixed a speed problem using this method.
by FIVESOLAS - 2009-04-01 11:18
Well, I have my router and modem sitting on top of each other. I have Comcast, speedboost. I am getting a roughly 20MG download, and a 10meg up. My suggestion is just upgrade.
by zheyan - 2009-05-23 22:02
YOU ROCK!!!! This solved my problem immediately....thank you so much!!!
by anonymous - 2009-07-06 12:55
I moved my router and modem apart and it doubled by speed! Many thanks for the suggestion!
by Jamie - 2009-07-12 10:31
KUDOS!!! Worked like a charm. Much obliged.
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