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Not getting full Gigabit speed

Frequent Visitor

Not getting full Gigabit speed

I had Gigabit installed on Saturday and have not seen speed above 800mb which I have only hit once or twice.  Speed are typically 500 - 600mb.  I'm using a Motorola MB8600 modem and all my levels look good.  Has anyone else experienced this (Seattle/Tacoma Area).

 

p.s. Speed are the same wheather I connect direct to modem or thru ASUS RT68U router.

 

Any asistance appreciated.

Connection
   Startup Sequence    
   Startup Step Status Comment

  
   Acquire Downstream Channel 543000000 Hz Locked
  
   Upstream Connection OK Operational
  
   Boot State OK Operational

  
   Configuration File OK d11_m_mb8600_gigabit_c01.cm
  
   Security Enabled BPI+
  


   Connection Status    
   System Up Time 2 days 20h:27m:00s.00  
  
   Network Access Allowed  
  


   Downstream Bonded Channels  
  
   Channel Lock Status Modulation Channel ID Freq. (MHz) Pwr (dBmV) SNR (d Corrected Uncorrected
1 Locked QAM256 1 543.0 3.9 38.2 1139 0
2 Locked QAM256 2 549.0 4.4 38.2 1419 0
3 Locked QAM256 3 555.0 4.2 38.3 1443 0
4 Locked QAM256 4 561.0 4.5 38.2 1815 0
5 Locked QAM256 5 567.0 4.7 38.2 2137 0
6 Locked QAM256 6 573.0 4.8 38.1 2143 0
7 Locked QAM256 7 579.0 4.6 38.3 2279 0
8 Locked QAM256 8 585.0 4.4 38.0 2769 0
9 Locked QAM256 9 591.0 4.6 37.9 3336 0
10 Locked QAM256 10 597.0 4.4 38.0 2960 0
11 Locked QAM256 11 603.0 4.1 38.0 3652 0
12 Locked QAM256 12 609.0 3.8 37.9 4657 0
13 Locked QAM256 13 615.0 3.6 37.8 5544 0
14 Locked QAM256 14 621.0 3.5 37.8 5414 0
15 Locked QAM256 15 627.0 3.2 38.0 4648 0
16 Locked QAM256 16 633.0 3.4 37.3 5612 0
17 Locked QAM256 17 639.0 3.1 37.5 6415 0
18 Locked QAM256 18 645.0 3.1 37.5 7328 0
19 Locked QAM256 19 651.0 3.4 37.6 6420 0
20 Locked QAM256 20 657.0 3.3 37.7 5994 0
21 Locked QAM256 21 663.0 3.5 37.6 5295 0
22 Locked QAM256 22 669.0 3.2 37.2 5363 0
23 Locked QAM256 23 675.0 3.4 37.6 4692 0
24 Locked QAM256 24 681.0 3.4 37.5 5304 0
25 Locked OFDM PLC 159 745.0 3.4 36.5 0 0


   Upstream Bonded Channels  
  
   Channel Lock Status Channel Type Channel ID Symb. Rate (Ksym/sec) Freq. (MHz) Pwr (dBmV)
1 Locked SC-QAM 4 5120 23.7 35.0
2 Locked SC-QAM 1 5120 30.1 35.5
3 Locked SC-QAM 2 5120 36.5 35.5
4 Locked SC-QAM 3 5120 17.3 35.5

Accepted Solutions
Frequent Visitor

Re: Not getting full Gigabit speed

Thanks @ teron678

 

Solved!

 

After disabling the firewall and disabling Jumbo frames I'm getting 800 - 900mb on a fairly regular basis.  I also changed the patch able I was using from the modem to the router; although not sure that was an issue it was rated CAT6A.

 


All Replies
Problem Solver

Re: Not getting full Gigabit speed

I don't know for sure if this is correct but I had to get a 1 gig card to get over 100mb speed. If you have a 1 gig network card you will never get 1 gb speed. You need at least a 10 gb network card to get 1 gb speed.

Expert

Re: Not getting full Gigabit speed

FWIW, if one is subscribed to the gigabit speed tier, one technically should be able to get around 940 Mbps (due to the inherent ethernet overhead) with equipment that has a gigabit port negotiation / capability.

Frequent Visitor

Re: Not getting full Gigabit speed

corgi11 - Thanks for the reply.  However I sure I should be able able to hit speeds of 940mb max with Gigabit connection (w Gig card).  So I would expect speeds to be typically 850mb to 900ish mb without issue.

Contributor

Re: Not getting full Gigabit speed

Are you using beta.speedtest .. to test your speed if not try it and see if you get the same results. Also do you have a firewall program and QOS feature enabled in router setting disable them to see if that helps.
Frequent Visitor

Re: Not getting full Gigabit speed

Thanks @ teron678

 

Solved!

 

After disabling the firewall and disabling Jumbo frames I'm getting 800 - 900mb on a fairly regular basis.  I also changed the patch able I was using from the modem to the router; although not sure that was an issue it was rated CAT6A.

 

New Poster

Re: Not getting full Gigabit speed

Enabling Cut-Through Forwarding (CTF) in your router may remove the bottleneck. I had custom firmware (Tomato) on my Tenda AC15, and was only getting ~250Mbps.

 

After I enabled CTF, I was able to get near/Gigabit speeds.

New Poster

Re: Not getting full Gigabit speed

In response to this post:   (trying to not sound rude  Smiley Happy  )

 

"I don't know for sure if this is correct but I had to get a 1 gig card to get over 100mb speed. If you have a 1 gig network card you will never get 1 gb speed. You need at least a 10 gb network card to get 1 gb speed."

 

 

This is incorrect!  A Gigabit ethernet card is capable of pulling down up to 1 Gigabit speeds (1000 mb/s).  That is the whole point of it being called Gigabit.  Older computers from about 8 years ago or more had 10/100 cards and the maximum they could theoretically pull down was 100 mb/s.  Almost every modern computer and laptop (if it has a ethernet port) is a Gigabit ethernet port these days.  

 

 

 

Problem Solver

Re: Not getting full Gigabit speed

If you want full speed of the gig tier, then yes technically you would need 10G Ethernet. A 1G would max out at around 940 down (which isn’t the full speed of the tier). Even with 10G Ethernet port on your computer I believe that no modem or gateway available for use with Comcast does not have 10G Ethernet ports on them either so you are limited to about 940 down max.