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New MB8600 Cable Modem Installed - Is Speed as expected?

Frequent Visitor

New MB8600 Cable Modem Installed - Is Speed as expected?

Just upgraded from an Arris TM822G (now dropping the voice service) to a new Motorola MB8600 installed and activated the new MB8600 last night. I have Extreme Pro service from Comcast. Previously with the TM822G I was getting results from the Comcast Speed Test of 140 to 175 Mbps down / 11.3 Mbps up. Now with the new MB8600, the Speed Test results are higher and vary more widely : 200 Mbps to 290 Mbps down / 11.5 up. Should I be getting closer to 400 Mbps?

 

Here is my Modem Signal report:

M8600_Status_2018-06-21.jpg

Problem Solver

Re: New MB8600 Cable Modem Installed - Is Speed as expected?

Are you running the Speed test directly wired to the modem? No other programs running that will use up your bandwidth, including antivirus and other security software? Running speed test at a relatively quiet time of day or night? 


"Sometimes the best way to learn something is by doing it wrong and looking at what you did." - Neil Gaiman
Frequent Visitor

Re: New MB8600 Cable Modem Installed - Is Speed as expected?

Darkangelic,

The first few tests I ran last night were with my PC connected directly to the modem. With that connection, I had several results that were closer to 300 Mbps. I am now connected thru my Netgear R9000 router (wired GigE connection) and the results are a little lower (just ran one a minute ago and got 273.0 down / 11.1 up). I am running Norton antivirus. My PC is an i7-6700K, 4.2 GHz, so pretty fast machine. 

 

I can go back to direct connection to modem and stop the A/V if you think that will make a big difference?

 

I am not very knowledgable about Speed Tests and how they account for other internet traffic in the link between the test node and my machine (does this make a difference?), in addition to the other program activity on the PC being used? I also noticed that my latency has ranged from a low of 7 msec to a high of 13 msec (are these latencies as expected?) and that some tests are run in IPV6 mode and some in IPV4 mode (does that make a difference in speed results)?

Valued Contributor

Re: New MB8600 Cable Modem Installed - Is Speed as expected?

What is the actual quoted speed of that package?  The tiers vary by location but seeing that you have an OFDM lock on ch.32 I would assume it is the 400mbit tier.  If you are running windows 10 I would suggest getting the speedtest.net windows app rather than testing through the browser as that tends to bog down with faster speeds.  As far as the latency goes it depends on the distance to the test server you are going to and 7-13ms means you must be pretty close to where it is sending out to.  Unless you are going super far 10-40ms is usually pretty average.  

Expert

Re: New MB8600 Cable Modem Installed - Is Speed as expected?


@Ronny_Cordova wrote:

 but seeing that you have an OFDM lock on ch.32 I would assume it is the 400mbit tier.  .  


To my knowledge, if one's local system has indeed been upgraded to DOCSIS 3.1 with a downstream OFDM carrier, it will always be present / configured on the CMTS no matter which speed-tier one is subscribed to ? Please correct me if I am wrong or if this has now changed.

Silver Problem Solver

Re: New MB8600 Cable Modem Installed - Is Speed as expected?

Extreme Pro is 400/10 for the regions that have that tier. I have Blast! 100/10 and the OFDM has always been locked.

Valued Contributor

Re: New MB8600 Cable Modem Installed - Is Speed as expected?

I was just referencing the OFDM carrier in regards to the available speed tiers since you won't see the 400mbit package in a market that hasn't launched 3.1 yet (at least you shouldn't).  That extreme pro tier was available pre-3.1 roll out and is still in some markets but provides a completely different speed.  

 

You are correct though, if the OFDM is active you should always see a lock on 3.1 devices to utilize the additional bandwidth regardless of your package tier.  

Silver Problem Solver

Re: New MB8600 Cable Modem Installed - Is Speed as expected?

Not heard of different speeds for Extreme Pro. Here anyway, we get the tiers Extreme 300/25 and Extreme 150/20, but thanks!

Frequent Visitor

Re: New MB8600 Cable Modem Installed - Is Speed as expected?

New developments: I tried a different speed test website: 

http://www.comcast.speedtest.net/ : 483 Up / 12 Down / 7 ms Ping

This speedtest.net site is consistently measuring download speeds at 480 Mbps +/-  5%

The http://speedtest.xfinity.com/ site is giving extremely variable results, anywhere from 175 Mbps to 320 Mbps (highest seen) download speed, with the average at about 250 Mbps.

 

Which speedtest site should I believe?

 

 

Problem Solver

Re: New MB8600 Cable Modem Installed - Is Speed as expected?

If you're able to hit that speed on any site on the internet, you're getting your paid for speed tier.


"Sometimes the best way to learn something is by doing it wrong and looking at what you did." - Neil Gaiman
Frequent Visitor

Re: New MB8600 Cable Modem Installed - Is Speed as expected?

Ah good to know. Thanks Darkangelic.

Just curious -- Do you typically see lower speeds and more variability from the speedtest.xfinity.com site than the others? You would think that comcast would want customers to see the highest possible speed (but measured in a legitimate way) using their official site to avoid getting lots of complaint calls.

Problem Solver

Re: New MB8600 Cable Modem Installed - Is Speed as expected?

That depends on a lot of things - obviously if the speedtest server is located within Comcast's network, it would theoretically give the fastest speeds, but that's not always the case. 

 

If I use the Comcast test, for instance, it directs me to the closest server (San Francisco, over 50 miles away), but if I use Ookla, the closest one picked is in a town less than 10 miles away from me, so I'll often get faster pings and uploads. 


"Sometimes the best way to learn something is by doing it wrong and looking at what you did." - Neil Gaiman
Frequent Visitor

Re: New MB8600 Cable Modem Installed - Is Speed as expected?

I live in Auburn, WA, about 30 miles south of Seattle and 15 miles north of Tacoma. I'm finding that the both the Xfinity speedtest and Ookla (speedtest.net) are selecting servers in Seattle or Tacoma. Not sure if I can figure out which routing has the fewest hops. Maybe there's a difference in the speedtest algorithms used - that could be a factor?

Frequent Visitor

Re: New MB8600 Cable Modem Installed - Is Speed as expected?

Yesterday, before I tried the speedtest.net (only was using xfinity speedtest) and measuring speeds around 250 Mbps, I called Comcast support. The support person was knowledgable and helpful and said I should be seeing speeds closer to 400 Mbps (but he didn't suggest trying speedtest.net). Anyway, he scheduled a Comcast service call for me today. The service guy arrived and I showed him the newer results with speedtest.net, ie 480 Mbps. He said that he never uses the Xfinity speed test -- uses only speedtest.net. He also looked at my signal levels and said they looked great. So we concluded that everything was working just fine. Problem solved.