Ethernet speeds seem capped/WiFi does not

[TurboGraffix64]

Hey All,

 

I have had a continuing issue with PC Ethernet speeds matching my ISP speeds. When it comes to the speed I am paying for, 400 Mbps, I am only getting about 120 Mbps when I have any PC connected via Ethernet. I have tested this on my home work PC, my personal PC, and partner's PC, and every time the speeds will not exceed 120 Mbps. I cannot find a solution to this problem. Even when I tried direct connecting each PC directly to the modem, I have the same issue. Everything shows only 120 Mbps download while I am getting the upload speed included in my ISP plan. Here is the kicker, when I use my WiFi I am seeing speeds of 300-400 Mbps no problem. I have contacted the router manufacturer and they told me to contact my ISP as it seems to be an error on their end. My ISP sent out a technician and everything checked out fine, hardware, lines, etc.. With everything going on with COVID-19 it has become harder to get any assistance from my ISP and the router manufacturer. 

 

Has anyone else had this issue and is there a solution to the issue? 

 

I have verified my Ethernet cables as Cat 5e and not damaged, purchased new cables and everything to test. 

 

Here is the hardware I am using:
Asus ROG GT-AC2900
Motorola E31U2V1 Modem
Asus Strix B450-F Motherboard
Cat 5e Cables

Attached is a photo of my Ethernet Status to show my adapter is functioning just fine. 

 

[Hairless Monkey Boy]

To rule out any router settings, have you tried resetting the router to factory defaults?

[Hairless Monkey Boy]

Just now, HairlessMonkeyBoy said:

To rule out any router settings, have you tried resetting the router to factory defaults?

never mind you said you plugged straight into the modem.

[TurboGraffix64]

3 minutes ago, HairlessMonkeyBoy said:

never mind you said you plugged straight into the modem.

Yeah I have tried factory resetting everything and still the same issues continue. My ISP says they don't know and Asus says they also don't know ha

[Hairless Monkey Boy]

@TurboGraffix64

Yeah that's F-ed.

[asquirrel]

I had a surge protector once with built-in cat5 surge protection. Except for one teeny tiny problem. This surge protector, made in 2019, was only capable of surge suppressing 100Mb/s ethernet, not gigabit. :rage: If you don't have that problem, the only things that make sense would be TCP stack settings on your PC (receive/send window size, MTU, etc) But if you never customized any of those, then idk why they would have gone crazy and got to such wrong values because the out of the box defaults should support gigabit all on its own.

[TurboGraffix64]

I have included photos of both tests to show the speed difference, they were both connected to the same Charter server for the test. 

Here is the PC Speed Test


Here is my mobile speed test

[TurboGraffix64]

8 minutes ago, asquirrel said:

I had a surge protector once with built-in cat5 surge protection. Except for one teeny tiny problem. This surge protector, made in 2019, was only capable of surge suppressing 100Mb/s ethernet, not gigabit. If you don't have that problem, the only things that make sense would be TCP stack settings on your PC (receive/send window size, MTU, etc) But if you never customized any of those, then idk why they would have gone crazy and got to such wrong values because the out of the box defaults should support gigabit all on its own.

Yeah I have not changed anything nor do I run it through a surge protector. It's the damnedest thing ever. 

[Coshy91]

All I can suggest is possibly get rid of the isp equipment all together and go and buy your own?

[TurboGraffix64]

3 minutes ago, Coshy91 said:

All I can suggest is possibly get rid of the isp equipment all together and go and buy your own?

That is my final step, ditch their modem, however I am trying to find the non-expensive options first to avoid spending more money. 

[Coshy91]

Just now, TurboGraffix64 said:

That is my final step, ditch their modem, however I am trying not the non-expensive options first to avoid spending more money. 

Obviously another thing you could do is take it to a friends house and see if you encounter similar problems there too. If i was a buying new networking hardware I'd look into a mesh system from Asus as they are really versatile.

[TurboGraffix64]

55 minutes ago, Coshy91 said:

Obviously another thing you could do is take it to a friends house and see if you encounter similar problems there too. If i was a buying new networking hardware I'd look into a mesh system from Asus as they are really versatile.

I am just gonna buy a dual-band wireless adapter for my PC since it seems my Wi-Fi speeds aren't capped to 120 Mbps lol

[Windows7ge]

I'm not certain here as you've tested most thing already but 120mbps is only slightly over the limit of a 100mbps link. I'm wondering if it's a hardware issue. Something stuck negotiating between 100/1000mbps.

 

All hardwired devices experience this?

[TurboGraffix64]

2 hours ago, Windows7ge said:

I'm not certain here as you've tested most thing already but 120mbps is only slightly over the limit of a 100mbps link. I'm wondering if it's a hardware issue. Something stuck negotiating between 100/1000mbps.

 

All hardwired devices experience this?

Yes, I have tested 3 PCs so far. The only other device I have available to try would be my PS4. 
 

I can tell you none of them have had any of their adapter settings changed in any way. Unless I can identify the issue I feel I have two band-aids for now.
1) Try a Cat6 cable
2) Buy a wireless adapter (Due to faster wireless speeds) 

[TurboGraffix64]

2 hours ago, Windows7ge said:

I'm not certain here as you've tested most thing already but 120mbps is only slightly over the limit of a 100mbps link. I'm wondering if it's a hardware issue. Something stuck negotiating between 100/1000mbps.

 

All hardwired devices experience this?

Tested my PS4, I know Sony servers aren't the best, but even my PS4 has a faster connection. 

[PyroTheWise]

Okay, since the PS4 shows a higher speed.  Try moving the ethernet cable from the back of the PS4 to the PC.  I would also move one of the PC calbes from the PC to the PS4 and retest the PS4.  

 

What happens?

[Windows7ge]

The only other thing I can suggest is try shutting down everything. Absolutely everything except a single PC, and the modem/router. See if the speeds come back. I wonder if there's a rouge device spitting garbage over the network.

 

Beyond this though. I'm out of ideas. Sorry.