LG 55CX TV - Slow internet speeds (over Ethernet and Wifi)

[Dervius]

So for the past few days I've been trying to figure out what's going on with the internet speed on my LG CX. I noticed I was getting some low quality streams via the Now TV app and used both Netflix's built in speed tester and a few sites (fast.com, speedtest.net) via the web browser to see what speeds I was getting. To my dismay, it was around 5Mb/s down. My TV is wired directly into my router and I get about 150Mb/s downstream speed, 30Mb/s upstream. Oddly, in all tests I was still getting 30Mb/s upstream.

So, I set about troubleshooting to see if I can pinpoint the issue:

• Disconnected the cable and connected via wifi (router sits about 2ft away from the TV) - Similar speeds
• Checked router config for any obvious issues, no change
• Disabled IPV6 on the router, no change
• Tried using Google DNS instead of the ISP DNS, no change
• Tried using a different cable (the one I use for my Xbox, which gets 140Mb/s more or less) - No change
• Use the old cable on the Xbox, gets 140Mb/s
• Change ports on the router, no change

I've had no joy finding anything online for slow internet speeds other than basic Wifi stuff (use 5GHz instead of 2.4GHz, change wireless channels etc.) which doesn't help. I thought it might be a software based problem as I had recently updated the firmware, so I did a factory reset of the TV. My speeds are now up to 90Mb/s downstream. Okay great, I go and sign back into all my apps and recalibrate everything.

That was yesterday, checking again today and I'm a about 26Mb/s average over several tests. This is boggling my mind as I can't seem to identify why or where that connection would have been bottlenecked.

For reference the TV is connected via CAT6 Ethernet directly into an ethernet port on a BT Smart Hub 2 (their pretty naff ISP provided router).

Has anyone else had any similar problems, or any network gurus suggest any other troubelshooting options?

 

[CD_93]

This sounds very "off and back on again" but have you had the TV completely discharged of power at any point during this?

My C6 starting behaving very strangely last week. Similarly it seemed to start struggling with Netflix - other devices and the router it is connected to were okay. YouTube buffering became terrible also. I don't know what speeds it was running but eventually it completely lost network connectivity. The networking functions in WebOS even greyed out. This made me panic as I thought the network card had just been fried or whatever.

Had to pull the power and hit the power button a few times to fully discharge. Once powered back up again it was happy away.

 

[Dervius]

This sounds very "off and back on again" but have you had the TV completely discharged of power at any point during this?

My C6 starting behaving very strangely last week. Similarly it seemed to start struggling with Netflix - other devices and the router it is connected to were okay. YouTube buffering became terrible also. I don't know what speeds it was running but eventually it completely lost network connectivity. The networking functions in WebOS even greyed out. This made me panic as I thought the network card had just been fried or whatever.

Had to pull the power and hit the power button a few times to fully discharge. Once powered back up again it was happy away.

Click to shrink...

This is probably sound advice, I've reset it without the QuickStart+ enabled, but not done a full cold restart so I'll give that a shot. If that solves the problem I'll be equally pleased and irritated after going through all the above.

 

[PorcoLighto]

Having a similar, albeit a bit different on my 65" unit. I have been too busy to proper diagnose but the TV would just start struggling to stream 4K HDR youtube content after a while, on wifi 100Mb down.

 

[gozu]

Does the CX still have a 100Mbps ethernet instead of 1 Gbps?

I have to connect my C9 wirelessly because wired is often too slow for BluRay movies (1917 is a slideshow).

edit: confirmed it's still 100Mbps, lol.

Use wifi. Forget this tv has ethernet. As a bonus it saves you a cable :)

 

[Dervius]

Does the CX still have a 100Mbps ethernet instead of 1 Gbps?

I have to connect my C9 wirelessly because wired is often too slow for BluRay movies (1917 is a slideshow).

edit: confirmed it's still 100Mbps, lol.

Use wifi. Forget this tv has ethernet. As a bonus it saves you a cable :)

Click to shrink...

Mentioned in the OP the situation is the same via Wifi, and 100Mb/s should still be plenty fast enough to stream 4k content.

EDIT - Looking more into it, apparently there is more high-bitrate content around than I realised, but even so I wouldn't expect that to be a particularly common occurrence. I did know about the 100Mbit ethernet port (which is... disappointing) but thought it was adequate.

 

[Heynongman!]

did this happen to start after the newest firmware? I haven't had network issues but my eARC started behaving erratically, audio cutting out and back in every so often or completely and never returning in some cases until I power off the tv and power it back on. If I switch to ARC I get no problems. My theory is they broke some shit trying to fix vrr

 

[Euler007]

confirmed it's still 100Mbps, lol.

Click to shrink...

A minority of people have download speed faster than that, and for streaming Netflix's UHD streams at 15.6mbps.

 

[gozu]

Mentioned in the OP the situation is the same via Wifi, and 100Mb/s should still be plenty fast enough to stream 4k content.

EDIT - Looking more into it, apparently there is more high-bitrate content around than I realised, but even so I wouldn't expect that to be a particularly common occurrence. I did know about the 100Mbit ethernet port (which is... disappointing) but thought it was adequate.

Click to shrink...

It doesn't matter what your problem is. Ditch the cable with the C9 and CX is a fast and hard rule unless you have a wifi router from 1950.

So, ditch the cable forever, and start testing exclusively with wifi as a first step. I recommend firmware updating/swapping your wifi router and seeing if that makes a difference. It'll help diagnose your issue.

 

[gozu]

A minority of people have download speed faster than that, and for streaming Netflix's UHD streams at 15.6mbps.

Click to shrink...

yes, it's fine for streaming because streams have very low bitrates but it's an absolute non-starters for Blu-Ray quality movies.

And honestly, having this amazing TV and NOT watching any BluRay ever would be tragic! :)

 

[Dervius]

did this happen to start after the newest firmware? I haven't had network issues but my eARC started behaving erratically, audio cutting out and back in every so often or completely and never returning in some cases until I power off the tv and power it back on. If I switch to ARC I get no problems. My theory is they broke some shit trying to fix vrr

Click to shrink...

I believe so yes, but to be honest I'd never done much by way of network speed testing since I set the thing up a few weeks ago.

A minority of people have download speed faster than that, and for streaming Netflix's UHD streams at 15.6mbps.

Click to shrink...

Fair point in general, but at the same time given the price of these sets and the minimal manufacturing cost difference it seems like a poor choice.

It doesn't matter what your problem is. Ditch the cable with the C9 and CX is a fast and hard rule unless you have a wifi router from 1950.

So, ditch the cable forever, and start testing exclusively with wifi as a first step. I recommend firmware updating/swapping your wifi router and seeing if that makes a difference. It'll help diagnose your issue.

Click to shrink...

I'm sticking with meausring via the cable for the time being as Wifi does introduce some additional unknowns, like interference from other devices, wireless channel interference from other routers etc.

The speeds I'm getting are still way below the maximum throughput of the port anyway, so the problem has got to be elsewhere.

Swapping a new router in is an option, but all my other wired devices are working fine so I'm leaning toward it being an issue with the TV. If I don't get anywhere soon I'll certainly try this out.

What I will say is that the problem seems to get progressively worse each day I test it.

 

[Euler007]

yes, it's fine for streaming because streams have very low bitrates but it's an absolute non-starters for Blu-Ray quality movies.

And honestly, having this amazing TV and NOT watching any BluRay ever would be tragic! :)

Click to shrink...

Someone streaming a BR rip from plex instead of an UHD BR on this TV should be arrested!

Edit : BR bitrate is 40mbps. UHD can go up to 144mbps but as low as 72.

 

[Dervius]

yes, it's fine for streaming because streams have very low bitrates but it's an absolute non-starters for Blu-Ray quality movies.

And honestly, having this amazing TV and NOT watching any BluRay ever would be tragic! :)

Click to shrink...

Surely that's if you're streaming high-bitrate 4k Blu Rays from a NAS or something similar. Most of my 4k content is via the streaming services or direct Blu Ray Player, o again 100Mb/s doesn't seem like a major issue.

 

[gozu]

I'm sticking with meausring via the cable for the time being as Wifi does introduce some additional unknowns, like interference from other devices, wireless channel interference from other routers etc.

Click to shrink...

You think I've never heard of wireless interference and didn't factor it in my answer?

Anyways, you do you. Clearly you know how to troubleshoot this ;)

 

[Rogue74]

I believe so yes, but to be honest I'd never done much by way of network speed testing since I set the thing up a few weeks ago.



Fair point in general, but at the same time given the price of these sets and the minimal manufacturing cost difference it seems like a poor choice.



I'm sticking with meausring via the cable for the time being as Wifi does introduce some additional unknowns, like interference from other devices, wireless channel interference from other routers etc.

The speeds I'm getting are still way below the maximum throughput of the port anyway, so the problem has got to be elsewhere.

Swapping a new router in is an option, but all my other wired devices are working fine so I'm leaning toward it being an issue with the TV. If I don't get anywhere soon I'll certainly try this out.

What I will say is that the problem seems to get progressively worse each day I test it.

Click to shrink...

I have a C8 and in the past have tried to test download speed via a wired connection. Every other wired device I own gets download speeds of over 150mbps with my xfinity plan. My C8 would at most get 50mbps . Many times far less. It seems little had changed with the C9 and CX. I think you are wasting your time troubleshooting this with a wired connection. LG just has shitty ethernet implementation.

With wireless I could consistently get will over 100mbps.
Stick with wireless like others are saying.

 

[Jindrax]

does lg have a facebook page? try sending a message if they do. i did that with my samsung tv

 

[tokkun]

I have a C8 and in the past have tried to test download speed via a wired connection. Every other wired device I own gets download speeds of over 150mbps with my xfinity plan. My C8 would at most get 50mbps . Many times far less. It seems little had changed with the C9 and CX. I think you are wasting your time troubleshooting this with a wired connection. LG just has shitty ethernet implementation.

With wireless I could consistently get will over 100mbps.
Stick with wireless like others are saying.

Click to shrink...

Opposite here. I had this problem a lot with my C9, but only when using wireless. After resetting the TV and sticking with wired only it hasn't come back at all.

There were a lot of posts out there about changing your Wifi settings to make them more compatible with the TV, but I didn't find it worth the hassle when the 100-Mb wired connection works for 99% of the stuff I throw at it.

yes, it's fine for streaming because streams have very low bitrates but it's an absolute non-starters for Blu-Ray quality movies.

And honestly, having this amazing TV and NOT watching any BluRay ever would be tragic! :)

Click to shrink...

The maximum bitrate for spec-compliant BD videos is 36 Mbps.
For 50-GB UHD BDs it's 92 Mbps.

It's only when you get to the higher capacity UHD BDs where it can go over 100 Mbps.

 

[sirap]

Wired performance has always been very inconsistent on my CX. Switched to a dedicated AP and it's much better, but these days I do everything on the Nvidia Shield so it's not much of an issue.

 

[Deleted member 279]

Sorry if you answered this but is it only the tv that gets slow speeds or all devices

 

[Dervius]

Update - I tried the cold restart and am currently getting around 90Mb/s wired but will keep monitoring.

One suggestion I've seen online is using a USB3.0-Ethernet adapter which appears to work with LG's line of TVs as an alernative the the apparently iffy Ethernet implementation the TV's have.

If I keep hitting the issue I'll look into it.

 

[Dervius]

Sorry if you answered this but is it only the tv that gets slow speeds or all devices

Click to shrink...

Literally just the TV. All other wired and wireless devices are fine.

It's running OK at the minute since a cold reboot but we'll see how it goes.

 

[Deleted member 279]

Literally just the TV. All other wired and wireless devices are fine.

It's running OK at the minute since a cold reboot but we'll see how it goes.

Click to shrink...

im not familiar with troubleshooting internet on a tv but im familiar with networking in general.

speed issues can come from a few different things:
1) network congestion (slow speeds or too many devices)
2) damaged hardware
3) device configuration
4) component bottlenecking (ports with limited speeds or network chip having low max speed)
4) area outages

How do you perform the speed test on the tv? Are you able to browse to Ookla?

I assume everything else has good speeds? If youre hard wiring, confirm the speed of one device connected to port 1 in your router and then check the speed of the tv in port1 to see if its similar.

the purpose of this is to be 1000% sure if its the tv and not anything else.

If its the tv, browse for any background settings that need the internet. Many of these tvs actually have microphones like an alexa so that you can use voice commands. This could be interfering with your streaming speeds.

next id try factory resetting the tv if possible. Many times factory resetting an internet capable device will have it perform a function that can correct internet settings.

if none of this works, the next few obvious things would be

1) update firmware
2) call tech support for advice
3) check the manual for internet settings or guidance
4) use warranty for replacement
5) try different settings on router over ethernet or wifi
6) if all else fails, then theres probably nothing you can do

 

[gozu]

Opposite here. I had this problem a lot with my C9, but only when using wireless. After resetting the TV and sticking with wired only it hasn't come back at all.

There were a lot of posts out there about changing your Wifi settings to make them more compatible with the TV, but I didn't find it worth the hassle when the 100-Mb wired connection works for 99% of the stuff I throw at it.

when you get to the higher capacity UHD BDs where it can go over 100 Mbps.

Click to shrink...

tokkun the solution is to use a better wifi router, not to give up on 1% (and climbing) of movies.

I have had my TV for 7 or 8 months. I live in a crowded building, with over 20 wifi networks showing up, and I don't have a single momentary stutter on any single movie. None. Not a one. Why? The magic of buffering. Tiny ass wifi packet loss don't mean shit when you're streaming a movie or music. Non-interactive mediums are magical that way.

Yes, granted, maybe the interface of the TV when you go to internet-enabled apps like the LG store or Netflix or Plex will be faster on ethernet as a result of less jitter and packet loss. Menus are an interactive medium, after all but...

...I argue you will spend 99% of your time watching actual movies and 1% or less in menus, so it's not REALLY a choice after all if you ever want to watch BluRay quality.

Wireless all the way is the better solution unless:

1. You can't afford a working, modern wireless router (Don't just assume your wifi router is good, Too many are shit).
2. You are interested in Internet streaming only (netflix, amazon, hbo, apple, etc) and find their quality more than sufficient.

 

[Rogue74]

tokkun the solution is to use a better wifi router, not to give up on 1% (and climbing) of movies.

I have had my TV for 7 or 8 months. I live in a crowded building, with over 20 wifi networks showing up, and I don't have a single momentary stutter on any single movie. None. Not a one. Why? The magic of buffering. Tiny ass wifi packet loss don't mean shit when you're streaming a movie or music. Non-interactive mediums are magical that way.

Yes, granted, maybe the interface of the TV when you go to internet-enabled apps like the LG store or Netflix or Plex will be faster on ethernet as a result of less jitter and packet loss. Menus are an interactive medium, after all but...

...I argue you will spend 99% of your time watching actual movies and 1% or less in menus, so it's not REALLY a choice after all if you ever want to watch BluRay quality.

Wireless all the way is the better solution unless:

1. You can't afford a working, modern wireless router (Don't just assume your wifi router is good, Too many are shit).
2. You are interested in Internet streaming only (netflix, amazon, hbo, apple, etc) and find their quality more than sufficient.

Click to shrink...

Hang on. I'm confused by this post.

When you mention Blu Ray quality what are you referring to? I've seen you mention it across various posts. Are you referring specifically to ripping discs onto something like a Plex server? Because I never saw the OP mentioning he ever did that. From what I can tell the OP only streams from Netflix, Prime, whatever.

When I want the absolute the best quality I use a 4K blu ray player, but network speed is irrelevant there.

 

[tokkun]

tokkun the solution is to use a better wifi router, not to give up on 1% (and climbing) of movies.

I have had my TV for 7 or 8 months. I live in a crowded building, with over 20 wifi networks showing up, and I don't have a single momentary stutter on any single movie. None. Not a one. Why? The magic of buffering. Tiny ass wifi packet loss don't mean shit when you're streaming a movie or music. Non-interactive mediums are magical that way.

Yes, granted, maybe the interface of the TV when you go to internet-enabled apps like the LG store or Netflix or Plex will be faster on ethernet as a result of less jitter and packet loss. Menus are an interactive medium, after all but...

...I argue you will spend 99% of your time watching actual movies and 1% or less in menus, so it's not REALLY a choice after all if you ever want to watch BluRay quality.

Wireless all the way is the better solution unless:

1. You can't afford a working, modern wireless router (Don't just assume your wifi router is good, Too many are shit).
2. You are interested in Internet streaming only (netflix, amazon, hbo, apple, etc) and find their quality more than sufficient.

Click to shrink...

I have a good router running DD-WRT already. Most of the suggestions for getting compatibility with the TV involve disabling performance optimizing features on the router, such as wide band support or extended frequency ranges. It's just not worth spending the time and possibly degrading the rest of my network so I can baby LG's flaky Wifi implementation given the scarcity of content that needs > 100 Mbps.

If we ever get to the point where there are enough titles using > 100 Mbps bitrates, then maybe I'll reconsider. But honestly if that happens I would probably just buy a Shield or an Apple TV and stream to that using gigabit wired speeds. Which incidentally is a better option for CX owners to begin with, considering that LG removed DTS decoding in the 2020 TVs.

 

[BLEEN]

Try directly connecting to the modem.

 

[CD_93]

Wireless all the way is the better solution unless:

1. You can't afford a working, modern wireless router (Don't just assume your wifi router is good, Too many are shit).
2. You are interested in Internet streaming only (netflix, amazon, hbo, apple, etc) and find their quality more than sufficient.

Click to shrink...

3.

:-D

 

[tokkun]

Hang on. I'm confused by this post.

When you mention Blu Ray quality what are you referring to? I've seen you mention it across various posts. Are you referring specifically to ripping discs onto something like a Plex server? Because I never saw the OP mentioning he ever did that. From what I can tell the OP only streams from Netflix, Prime, whatever.

When I want the absolute the best quality I use a 4K blu ray player, but network speed is irrelevant there.

Click to shrink...

The discussion about 100 Mbps being insufficient only applies to streaming ripped, non-transcoded UHD Blu-rays. And even then it only applies to a small fraction of titles that make use of the higher bitrate options available when you use 66 GB and higher discs.

Whether using a standalone UHD BD player produces better quality is somewhat debatable. If you have a player that does tone mapping and you prefer the results to what the TV does internally, then fine. Personally I am done with swapping discs.

 

[Deleted member 279]

Another solution for OP, connect a laptop or streaming box.

 

[Dervius]

Another solution for OP, connect a laptop or streaming box.

Click to shrink...

This seems to be what many have done with AppleTV or Nvidia Shield boxes.

im not familiar with troubleshooting internet on a tv but im familiar with networking in general.

speed issues can come from a few different things:
1) network congestion (slow speeds or too many devices)
2) damaged hardware
3) device configuration
4) component bottlenecking (ports with limited speeds or network chip having low max speed)
4) area outages

How do you perform the speed test on the tv? Are you able to browse to Ookla?

I assume everything else has good speeds? If youre hard wiring, confirm the speed of one device connected to port 1 in your router and then check the speed of the tv in port1 to see if its similar.

the purpose of this is to be 1000% sure if its the tv and not anything else.

If its the tv, browse for any background settings that need the internet. Many of these tvs actually have microphones like an alexa so that you can use voice commands. This could be interfering with your streaming speeds.

next id try factory resetting the tv if possible. Many times factory resetting an internet capable device will have it perform a function that can correct internet settings.

if none of this works, the next few obvious things would be

1) update firmware
2) call tech support for advice
3) check the manual for internet settings or guidance
4) use warranty for replacement
5) try different settings on router over ethernet or wifi
6) if all else fails, then theres probably nothing you can do

Click to shrink...

Thanks for this as it's all sound network troubleshooting guidance. I've gone through most of these steps in one capacity or another, and the TV suffering slow speeds across Wifi and Wired, despite tryig different cables, ports, configs and all other devices continuing fine I'm lead to believe it's the TV.

A factory reset worked for a period of time but the speed dropped after a day, but a cold reboot today seems to have pumped them back up for a bit.

Speeds sitting around 90Mb/s atm wired, which is about what you might expect given the known limitations of the network chip. I'm going to do some speedtests both wired and wireless each day for a week and see what it looks like.

 

[Deleted member 279]

This seems to be what many have done with AppleTV or Nvidia Shield boxes.



Thanks for this as it's all sound network troubleshooting guidance. I've gone through most of these steps in one capacity or another, and the TV suffering slow speeds across Wifi and Wired, despite tryig different cables, ports, configs and all other devices continuing fine I'm lead to believe it's the TV.

A factory reset worked for a period of time but the speed dropped after a day, but a cold reboot today seems to have pumped them back up for a bit.

Speeds sitting around 90Mb/s atm wired, which is about what you might expect given the known limitations of the network chip. I'm going to do some speedtests both wired and wireless each day for a week and see what it looks like.

Click to shrink...

sounds like the best option is a google chromecast or a dedicated media pc.

 

[gozu]

LG's flaky Wifi implementation

Click to shrink...

The C9 is not flaky for me using 4 different wifi routers. Including 2 TP-Links, a bundled one from Spectrum and an ancient Apple airport extreme. The stats point to your wifi router honestly, rather than the TV, unless the CX net stack is different than the C9, which I suppose is a remote possibility.

If we ever get to the point where there are enough titles using > 100 Mbps bitrates, thenI would probably just buy a Shield or an Apple TV and stream to that using gigabit wired speeds. Which incidentally is a better option for CX owners to begin with, considering that LG removed DTS decoding in the 2020 TVs.

Click to shrink...

Shield is good. I have gone one step further and I have a gaming PC hooked directly to the TV. Problem is the magic TV remote control for the LG Plex App is too convenient. I wish I had a great alternative to it.