C7000v2 WAY slower than Xfinity modem

[Sashen]

I just signed up for 600Mb Download speed from Xfinity.

I've BEEN using a C7000v2 with Xfinity for a while, but when I upgrade to the new speed I ran a speed test (WiFi) and get about +/- 260Mb.

With Xfinity's router, I'm seeing well over 600Mb down.

I'd LOVE to use the C7000v2. The Xfinity modem is LOUD and expensive.

Suggestions?

[plemans]

was the C7000 new? 

did you enable or has qos been enabled? it isn't recommended >250mbps as it disabled ctf (cut through forwarding) which allows speeds >250mbps. 

I've read of qos settings being retained even through a reboot. you could try factory resetting it. just make sure not to enable traffic meter or qos. 

Another thing you could do is have them re-provision it. I've had them send the wrong provision file before. 

Take a screen snip of your modem connections page. it shows the connection back to the isp. This helps check the signal

[Sashen]

I'm pretty sure I bought it new, but it's been a while since I did.

As far as I've been able to tell, there is no QOS setting/option on this device.

Traffic Meter has been off the whole time.

I can't send a screenshot since the only way to get it is if the modem is active, which it's not at the moment -- Comcast/Xfinity won't let me have both devices active at the same time (and, obviously then, I'm using the Xfinity modem at the moment).

[FURRYe38]

What are you wired speeds thru the NG modem? 

Have the ISP check the signal and line quality UP to the modem. 
Be sure there are not coax cable line splitters in the between the modem and ISP service box. 
Be sure your using good quality RG6 coax cable up to the modem. 

What channels are you using? Auto? Try setting manual channel 1, 6 or 11 on 2.4Ghz and any unused channel on 5Ghz.
Any Wifi Neighbors near by? If so, how many?

[Sashen]

I no longer own a computer with an ethernet port.

The Xfinity gives about 700Mb down via WiFi.

The NG gives about 260.

[FURRYe38]

What is the Mfr and model# of the ISP modem? 

Check the specs on the C7000v2, WiFi connection rates are:

(600 Mbps @2.4GHz with 256 QAM support +1300 Mbps @5Ghz 11ac)†

You need to check your wifi connection rates with WiFi Sweet Spots app loaded on your wireless devices. 

[Sashen]

There's no indication on the Xfinity modem of who the manufacturer is.

My C7000v2 is set up with those specs.

My computer is 3' away from the modem, so Sweet Spots isn't telling me anything meaningful.

[plemans]

You've made it a challenge. 

1. we don't know what the current modem is. Is it a docsis 3.1 device? if so, they tend to be a little more tolerant of connections back to the isp that aren't the best versus a docsis 3.0 device (which the c7000 is)

2. We dont' know what your hardwired speed from the C7000 is. Another key. wireless can be influenced by many different factors which is why we rely on hardwired speeds for the baseline. 

3. We don't know what the connection back to the isp was like. Again with the docsis 3.1 vs 3.0. 

Its tough to tell you anything without reliable info from the C7000. 

[Sashen]

I found an OLD computer with an ethernet port. The speed is stupidly slow... but 2x faster with the Xfinity modem.

I have no specs on the Xfinity modem so I can't tell which Docsis version it's using.

I would think that having 260Mb wireless speed with the NG and over 700Mb with the Xfinity, when both modems are 3' away from the computer would be a useful diagnostic.

[plemans]

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@Sashen wrote:

I found an OLD computer with an ethernet port. The speed is stupidly slow... but 2x faster with the Xfinity modem. OLD devices aren't always good. Some old devices can't max out gigabit speeds. But they at least give you a hardwired baseline. 

I have no specs on the Xfinity modem so I can't tell which Docsis version it's using.----a model number lets us look it up. Tends to be on the label.  

I would think that having 260Mb wireless speed with the NG and over 700Mb with the Xfinity, when both modems are 3' away from the computer would be a useful diagnostic.------its not. many things influence wireless from interference on a channel, to the environment, to hardware issues. Also, if the modem is only pulling 260mbps because it was partitioned wrong, has a sketchy signal only allowing 260mbps, then that's the bottleneck. We don't know currently and you haven't given us reliable data to work with. Wireless is an indicator but not that useful for diagnostics without more data. 

compare it to a car. Telling a mechanic my car will drive 120mph but my other vehicle that's rated to 120 will only go 65mph and then going "why isn't it as fast"? The mechanic can't tell you without more specifics. its an indicator of an issue but its not the full story and they can't tell you for sure what the issue is without those details.  

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[Sashen]

Cutting to the end of the story: After 3 hours on the phone with Netgear, they're sending me a replacement unit.

Fingers crossed.