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Gigabit Speed Slow

Frequent Visitor

Gigabit Speed Slow

Just had gigabit installed on June 1.  Speed was ~400 Mb/s down and 40 Mb/s up.  Since then it averages 250-350 down and a constant 40 up.  The speed is the same as my old Blast tier.  I have the Gigabit Internet tier and the Technicolor CGM4140COM Gateway.

 

 

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Expert

Re: Gigabit Speed Slow

The biggest thing I see with that is that the SNR for the OFDM channel is extremely low.

Try resetting it to factory settings by holding the rest button for 60 seconds. Are these speeds over Wi-Fi or hardwired?


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Frequent Visitor

Re: Gigabit Speed Slow

Wired into the gateway.  I've already done a hard reset.

Expert

Re: Gigabit Speed Slow

@Bosty

First, make sure you are actually on the gig speed tier. Visit https://mydeviceinfo.xfinity.com to determine your speed tier. After you log into your account, your speed tier will be displayed on the left-hand side of your screen. Alternatively, you can view the speed tier to which you are subscribed here. Sign in and scroll down to the data usage graph area.

 

Other things to try:

  • Disable your antivirus/firewall briefly and check speeds.
  • Boot your computer into safe mode w/networking and check speeds.
  • Verify that you meet the system requirements. 

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Frequent Visitor

Re: Gigabit Speed Slow

So I tried the above suggestions and no improvement. I had a tech out today and he hooked up a little black box to the gateway and ran a speedtest over wifi and he got 940 Mb/s. So I told him to remove the black box and test again over the gateway wifi and, surprise, the speed was back to 350 Mb/s. Told him there is no reason why the speed should be different and that the little black box inflates the numbers. He proceeded to tell me that there is no reason any residential customer needs 1 GB speed anyway unless you are running a big business. Getting tired of techs who are really quite incompetent in their job. So I guess that Comcast expects us to pay for 1 GB tier but has no way to actually get us that speed. Anyone else have any ideas since Comcast is pretty clueless?
Regular Contributor

Re: Gigabit Speed Slow

Comcast doesn't guarantee wireless speeds at all, only what's coming directly out of the gateway. And it sounds like the tech proved it.. Not much else you can do about it, except get your own gear and see if it makes a difference. If it's still the same, you'll know it's all in your personal equipment.
Frequent Visitor

Re: Gigabit Speed Slow

Not sure how he proved it. He could not get a wifi signal of 940 Mb/s through the gateway, only a wifi signal of 940 Mb/s through his "little black box". Either the gateway is bad, in which case how did he get the high speed or his black box gives fake readings and is probably a signal booster. There is no way he can get the speed through his box but can't get the speed directly since they both used wifi signal. The only variable is the black box.
Regular Contributor

Re: Gigabit Speed Slow

I don't know if you weren't paying attention or not but that black box, plugs directly into the gateway, it's not wireless.
Frequent Visitor

Re: Gigabit Speed Slow


@Wolverine062 wrote:
I don't know if you weren't paying attention or not but that black box, plugs directly into the gateway, it's not wireless.
I was and he connected to the box with his phone and used a WiFi signal. The box plugged into the gateway via Ethernet cable. Unless the iphone has a mysterious way to connect directly to the black box, it used a WiFi signal. He did not use a computer at all.
Expert

Re: Gigabit Speed Slow

The device is hard wired to the gateway and connects to their phone wirelessly to tell them the speed it is reading.


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Frequent Visitor

Re: Gigabit Speed Slow

OK, that makes sense. Thanks for the clear explanation.. Any ideas since I exceed the requirements for PC specs and use cat 7 cable directly connected to modem? Is it just hit or miss with their service?
Expert

Re: Gigabit Speed Slow

I’m not sure what else to tell you for over Wi-Fi but try to in the gateway settings to use higher number channels and higher bandwidth settings in an attempt to try to push more through the Wi-Fi. Also do you happen to know what kind of Wi-Fi card you are using.

For Ethernet side of it just make sure it’s at 1Gbps Full-Duplex


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Frequent Visitor

Re: Gigabit Speed Slow

I use Ethernet cat 7 cable to connect. I don't use wifi except for the house.. My network adaptor says 1 Gbps speed. Under the duplex option, I have 10 Mbps Half; Duplex; 10 Mbps Full; Duplex; 100 Mbps Half; Duplex; 100 Mbps Full; Duplex and Auto Negotiate. Should there be a 1000 Mbps Full Duplex option?
Expert

Re: Gigabit Speed Slow

I believe their should be or at least auto negotiate. Try checking for driver updates for your Ethernet adapter.


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I am just a customer, volunteering my time to help other customers here in the Forums.
We ask that you post publicly so people with similar questions may benefit from the conversation.

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