DOCSIS modem upgrade from 3.0 to 3.1 worth it?

B

biggles

2[H]4U
Joined
Jul 25, 2005
Messages
2,221
As an Amazon Associate, HardForum may earn from qualifying purchases.
criccio said:
What plan are you paying for?

You're testing wired, right? Not over Wifi?
Click to expand...
The name of the Xfinity plan we have is called Blast Internet. Yes, testing was done using PC in signature wired with ethernet cable.
 
What is your upload speed?

Your modem is EOL and should be replaced soon. Go with a Arris S33.
https://www.amazon.com/ARRIS-Surfboard-S33-Multi-Gigabit-Ethernet/dp/B08FMSC5WZ

Check here to see what Xfinity speeds are available in your area --> https://broadbandmap.fcc.gov/home

Blast Internet is a legacy plan. I would call them to negotiate a new plan.

I got the same email. I'm on Fast Internet and get 500/20 with my ancient XB3 gateway. I'm going to wait to upgrade until mid-split is available in my area. Highest speed for my area is 1200/35. I'm in the Philly burbs.
 
Last edited:
As an Amazon Associate, HardForum may earn from qualifying purchases.
Follow-up question: my router is the TP-Link AX1800 (Archer AX21). How fast are the LAN ports on this WiFi 6 router? I can't find this information on the Amazon listing. Hopefully fast enough to take advantage of the 1200 Mbps that is theoretically possible through Xfinity.
 
biggles said:
Follow-up question: my router is the TP-Link AX1800 (Archer AX21). How fast are the LAN ports on this WiFi 6 router? I can't find this information on the Amazon listing. Hopefully fast enough to take advantage of the 1200 Mbps that is theoretically possible through Xfinity.
Click to expand...
https://www.tp-link.com/us/home-networking/wifi-router/archer-ax1800/#specifications

You'd need a router with 2.5Gb WAN and LAN ports to make use of anything over Gigabit.

Its Xfinity though, good luck reliably getting 1200Mb/s reliably.

1717179231783.png
 
biggles said:
Current modem is TP-Link TC-7620 which has a theoretical max download speed of 686 Mbps. I did a speed test yesterday and got a result of 494 Mbps.
Click to expand...
You don't need a new modem unless you're looking to upgrade your plan to a higher speed.

I would rent a modem if you're looking to upgrade your plan to Superfast (800Mbps) or higher. No reason to buy a new modem until mid-split (Next Gen Speed Tier) is available in your area. Mid-split enables higher upload speeds (75-200Mbps).

Your router is fine up to the Gigabit plan (1000Mbps).

https://www.xfinity.com/learn/internet-service
https://www.xfinity.com/support/articles/upgraded-areas-leased-equipment-required-for-upload-speeds

https://assets.xfinity.com/assets/dotcom/projects/cix-4997_compatible-devices/2024.04.03 Full List of Compatible Devices.pdf
 
Last edited:
biggles said:
Yes, that is why I worded my post "theoretically". My guess is real world speeds are nowhere close to 1200 Mbps. And it does not seem to router upgrade time yet all things considered.
Click to expand...
If you have a good signal Comcast will give you 20% more than plan speed. That's common knowledge on Comcast's forums. They overprovision a bit to compensate for a lot of customers being on marginal cable plant or having marginal equipment. My signal strength is absurdly spectacular for Comcast. I get 1400-1440/~40 on a 1200/35 plan all day every day. In theory I should have a 1200/200 plan, but Comcast yanked the approval from my NetGear CM2050V modem a month or two after approving it for DOCSIS 3.1 upload. I had an OFDMA channel locked, but apparently people had connection stability issues with it so they rolled us all back to DOCSIS 3.0 upload. I'd volunteer for a beta program to get my OFDMA channel back. I never had any trouble the first time, but again my connection is SHINY. Like stayed up for a year, the connection time counter on my modem rolled over and started displaying negative numbers, and only went down because the electric company had a power failure. I've been on Comcast's forums and compared signal strength numbers and, well, I don't think I've seen any as good as mine.

Don't take this as a recommendation for Comcast. My results are not typical. If you've had them and hate them that just means I have better Comcast luck than you do, which is very good for me because those bastards from AT&T don't provide fiber service to my house even though it's a couple blocks away in all directions. Maybe they'd do it if I hounded them, but for now I don't need to bother.
 
As mentioned before, unless you plan on upgrading to that 1.2Gbps plan; I wouldn't bother upgrading. I'm guessing you're on a 500Mbit/s plan, so your existing modem is plenty fast enough for that.

Additionally, once you break the 1Gbps internet speeds you need to worry about a firewall that can handle that much bandwidth, and switches, network cards, wifi, cabling that can handle 2.5G or better.

I have an Arris SB8200 and have 900Mbps through Xfinity. I can usually get close to 950Mbps when running tests. I was running a SB6183 until I went to 900Mbps. Had to upgrade both my modem and firewall to handle the additional bandwidth.
 
I think Comcast advertised new modems to take advantage of higher upload rates with the new DOCSIS 3.1 modems. The upload speed increase is a free upgrade as long as you have a modem that can do it. Downspeed should be about the same from what I've been able to gather unless if you're going with one of their 2Gbps lines.
 
Stugots said:
As mentioned before, unless you plan on upgrading to that 1.2Gbps plan; I wouldn't bother upgrading. I'm guessing you're on a 500Mbit/s plan, so your existing modem is plenty fast enough for that.
Click to expand...
One exception is if your connection suffers from local network congestion during busy times. Even if you only have a 500 or whatever Mbit plan a DOCSIS 3.1 modem can still use the OFDM line and may perform better during busy times. So it might help if you have a lot of neighbors with DOCSIS 3.0 equipment and you get full speed late at night, early in the morning, etc. but it slows down in the evening or whatever.

And yeah, for anything over 1Gb you need better than 1Gb wired or some shiny WiFi gear and a low interference environment.

Toboggan said:
I think Comcast advertised new modems to take advantage of higher upload rates with the new DOCSIS 3.1 modems. The upload speed increase is a free upgrade as long as you have a modem that can do it. Downspeed should be about the same from what I've been able to gather unless if you're going with one of their 2Gbps lines.
Click to expand...
They've supported DOCSIS 3.1 download for years. IIRC you need 3.1 for 1Gb and faster download. The modems supported for increased upload on Comcast are a small subset of the modems that will support DOCSIS 3.1 OFDM download on Comcast's network.
 
Stugots said:
As mentioned before, unless you plan on upgrading to that 1.2Gbps plan; I wouldn't bother upgrading. I'm guessing you're on a 500Mbit/s plan, so your existing modem is plenty fast enough for that.

Additionally, once you break the 1Gbps internet speeds you need to worry about a firewall that can handle that much bandwidth, and switches, network cards, wifi, cabling that can handle 2.5G or better.

I have an Arris SB8200 and have 900Mbps through Xfinity. I can usually get close to 950Mbps when running tests. I was running a SB6183 until I went to 900Mbps. Had to upgrade both my modem and firewall to handle the additional bandwidth.
Click to expand...
Cat5e easily handles 2.5GbE. I have a 150'+ run that was installed 24 years ago. Modem/Router and secondary PC are upstairs and my main PC is at the end of the run and I get full speed from my secondary PC to my main pc and plex server.
cox speed test 2356mbps.png

Battlenet speed.png

2.5GbE-Copy.jpg
 
criccio said:
You'd need a router with 2.5Gb WAN and LAN ports to make use of anything over Gigabit.
Click to expand...
Stugots said:
Additionally, once you break the 1Gbps internet speeds you need to worry about a firewall that can handle that much bandwidth, and switches, network cards, wifi, cabling that can handle 2.5G or better.
Click to expand...
^^THIS^^

It would make ZERO sense to upgrade your router or plan UNLESS your pc has an ethernet (or WiFi) card that supports speeds faster than 1G, regardless of what speeds your plan offers, it won't make a bit of difference with either download or upload speeds, since those are dictated by the slowest link in your setup....

This point almost always seems to get overlooked in these types of threads/discussions for some reason :)
 
dogDAbone said:
^^THIS^^

It would make ZERO sense to upgrade your router or plan UNLESS your pc has an ethernet (or WiFi) card that supports speeds faster than 1G, regardless of what speeds your plan offers, it won't make a bit of difference with either download or upload speeds, since those are dictated by the slowest link in your setup....

This point almost always seems to get overlooked in these types of threads/discussions for some reason :)
Click to expand...
Probably because we know we need NIC's that support it and don't have to keep mentioning it.

Btw, if you don't have an internal slot for a 2.5GbE Nic, these work just fine, I've used this on many PC's and my SteamDeck to get faster transfers on my network.
1717536983271.png
 
Zepher said:
Probably because we know we need NIC's that support it and don't have to keep mentioning it.
Click to expand...
Well, sometimes it does not appear this way, based on the way the posts are worded....

It seems as though some folks are STILL under the misconception that just because they up their ISP speed or switch to a faster router, that their internet speeds at their computers will just magically increase also....

That's why I said what I did :D

But yea, I've used those adapters for lappy's at work for several years now nottaproblemo....
 
Zepher said:
Cat5e easily handles 2.5GbE. I have a 150'+ run that was installed 24 years ago. Modem/Router and secondary PC are upstairs and my main PC is at the end of the run and I get full speed from my secondary PC to my main pc and plex server.
Click to expand...
Thank you for this data point. I have some nearly 30 year old 400Mhz rated wire (it was right before the cat standards kicked in) at my parents house that I think would be able to handle the same, but wasn't too sure. :)
 
Besides the modem upgrade nag, the biggest problem is that if you swap out your modem and want to go back, they won't let you connect an older, yet was previously working modem. Just something to keep in mind. imo if it isn't broken, dont' try to fix it.
 
Personally, I would think the newer one might enable more or better channels. Your speed might not go up but reliability may?
 
uberjon said:
Personally, I would think the newer one might enable more or better channels. Your speed might not go up but reliability may?
Click to expand...
I've heard this for decades now, but have never seen the difference. In one instance where they were the isps modems, I got newer modems to see absolutely zero improvements so went back and swapped back to my previous modems (I had 3x on my account).
 
biggles said:
Update, upgraded to the Arris S33 DOCSIS 3.1 modem. Speedtest download result = 945 Mbps. This was again on ethernet and a Windows 10 PC.
Click to expand...
Did you change your plan? I'm not sure what "Blast" is. Google says it's 400mbps, but it's not a current Comcast plan and Comcast occasionally changes their plans. Mine went from 150 to 600 between 2017 and 2022. At any rate 945 is about the best you'll get over 1Gb ethernet.
 
Did you document your upload speeds before the swap? I'm curious if that changed too?

With that big of a speed increase id bet your new modem is locking more downstream channels than the old modem. More channels imo can improve stability.
 
I did not change my internet plan. The modem upgrade was in response to an email from Xfinity saying that the old one was holding back download speeds. In the email Xfinity said I could get up to 1200 Mbps with a DOCSIS 3.1 modem.

I did not record the upload speed prior to the upgrade. The new upload speed is 42 Mbps, FWIW.
 
biggles said:
I did not change my internet plan. The modem upgrade was in response to an email from Xfinity saying that the old one was holding back download speeds. In the email Xfinity said I could get up to 1200 Mbps with a DOCSIS 3.1 modem.

I did not record the upload speed prior to the upgrade. The new upload speed is 42 Mbps, FWIW.
Click to expand...
That would explain the performance you were getting and why Comcast was sending you emails. If you have a speed plan your modem doesn't support you'll often get kneecapped. Your modem often won't run at it's maximum speed if it's too slow for the plan you have. Since you're getting 945 now and haven't changed plans that means your plan speed is at least 800. That wouldn't surprise me. Comcast tends to overprovision by about 20%, so if everything is working perfectly it's possible to get 945 on an 800 plan. I figure they do it to reduce complaints and lower customer support costs. Comcast changes their pricing and plan speeds occasionally, and usually what they do is just increase speed at the same price. I signed up for 150 in 2017 and by early 2022 I had 600 with no rate increases for Internet. Then in early 2022 I dumped cable TV, got a new modem and upgraded my Internet speed to 1200/35.
 
You must log in or register to reply here.
Back
Top