Question Only getting 250ish Mbps with 343Mbps Modem why ??

Davv

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Sep 29, 2010
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I have a Arris SB6141 which is rated at 343Mbps. This is happening with and without the router by the way. The ethernet cable is a Cat5e that's 6 foot long. My router is a ASUS RT-N66U Gigabit Router, both of the these items are only 2-3 years old. The only thing that changed was my Spectrum internet plan went from 100/10 to 400/20. I know I shouldn't expect 400Mbps with the modem but I should at least get in the low 300's right ?
 
You need to check the compatibility lists. Even though the modems in theory can run some speed many of the ISP run them at slower speeds. In many cases you will find a ISP says to get more than 100m you need a 16x4 or 32x8. I know to get the 1gbit plans they want docsis 3.1 even though that technology can run 10g.

So check the list of supported modems by plan. I bet you are going to need a better modem.
 
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Davv

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I think I've decided to get the Asus RT-AC68U router, ARRIS Surfboard (32x8)(SB6190) DOCSIS 3.0 1.4 Gbps Max Speed.

I checked the Spectrum modem recommended list and the SB6183 rated for 686 Mbps doesn't even cut it for 400 Mbps plans.
 
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Check several sites. Fast.com and speedtest.net are the usual speed test urls I use. (Although speedtest.net doesn't work as well with larger connections)

That said, you need to also eliminate as many links from cable modem->computer as possible. You can direct connect the computer via ethernet to the cable modem. Test it that way.
 
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Andreas Schmidt

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Feb 7, 2014
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The best test is to test .BIN file i always test bin files to test download speed download internet download manager, copy one of this links and put there start download and watch the speed. in mb/s , but u dont need to download the file just check speed, and cancel. i prefer 1GB file. but dont expect to be exactly 400Mbps.
If u get in download manager 45 MB/s Is ok . 400Mbps 47.68 MB/sec here is list of site test some of them.


  1. https://speed.hetzner.de/
  2. https://boekee.net/speedtest/
  3. http://speedtest.tele2.net/
  4. https://www.linode.com/speedtest
  5. https://www.thinkbroadband.com/download
  6. http://speedtest.novoserve.com/
  7. https://ftp.bit.nl/speedtest/
  8. http://speedtest.reliableservers.com/
  9. https://mirror.nforce.com/pub/speedtests/
  10. http://speedtest.serverius.net/
  11. http://www.ovh.net/files/
  12. https://www.hostkey.com/support/speedtest
  13. https://www.hostkey.com/support/speedtest
  14. https://mirror.leaseweb.com/speedtest/
 

AtkinsFriendly

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May 26, 2015
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You need to check the compatibility lists. Even though the modems in theory can run some speed many of the ISP run them at slower speeds. In many cases you will find a ISP says to get more than 100m you need a 16x4 or 32x8. I know to get the 1gbit plans they want docsis 3.1 even though that technology can run 10g.

So check the list of supported modems by plan. I bet you are going to need a better modem.

I'm going to agree with Bill on this one. It's sounding like your going to neeed a 16x4 or 32.

On older cable infrastructures, it is required to get more channels to gain speed downloading.