RT-AC86U LAN at 1/2 speed of wireless

[dwagar]

I'm new here, so I'll apologize up front if I've posted this in the wrong section.

My ISP did a free upgrade from 150 to 300. I've been using an AC-66U, I thought the speed upgrade was a good excuse to upgrade my router to an 86U. It is impressive with 5G coverage in my house btw.

I installed the new Merlin firmware 384.8. I've read a ton of threads on settings. 5G on my phone is very close to 300.

WAN and LAN are both showing 1 gig.

But my hard wired PC will not get over 150.

I did test it direct to the modem. Same thing, 150. But since I am receiving 300 on wireless, I assume it's not a modem issue.

I assume it's a Windows 10 issue or something in the PC hardware. I built the PC in 2017, so it's not old hardware.

I've replaced my cables to Cat6.

I bought a new ethernet card (Intel Gigabit CT) in case there was a problem with the motherboard mounted port.

I've checked all drivers, upgraded the BIOS.

I even tried one of those wireless USB connectors, still under 150.

I'm at a loss. Can someone point me in the right direction?

TIA

 

[ApexRon]

There are several key items in your observations:

WAN and LAN are both showing 1 gig

...my hard wired PC will not get over 150

I am suspecting that while your ISP claims to be providing your with 300Mbps, your modem is not configured (by your ISP) for it or your modem is not capable of 300Mbps.

• Can I assume that you have a cable modem provided by your ISP?

 

[dwagar]

Yes, it is a cable modem provided by the ISP. Cisco DPC3848V

I am receiving very close to 300 on wireless though.

 

[ApexRon]

Yes, it is a cable modem provided by the ISP. I am receiving very close to 300 on wireless though.

But you said:

5G on my phone is very close to 300.

5G is a cellular connection.

 

[ColinTaylor]

5G on my phone is very close to 300.
:
But since I am receiving 300 on wireless, I assume it's not a modem issue.

Are you absolutely sure. How are you measuring the speed?

 

[ApexRon]

Wait a minute... I think I have decoded what you're saying:

The only problem you are having is associated with your PC. Your PC cannot get better than 150Mbps whether it's connected to the router or directly connected to the ISP modem. You have replaced the PC's Ethernet card with no change in speed. All other LAN or WiFi devices are testing at 300Mbps.​

Am I correct?

You built the PC yourself and you're running Windows 10. Dude, me thinks you have a PC issue.

 

[dwagar]

Yes. I think it's a PC issue. I don't have another LAN device.

I am testing with Ookla. App on my phone, Win10 App, and on Chrome, Chrome incognito, Edge.

 

[ColinTaylor]

Do you have any third party software installed on the PC that might effect the network connection, like firewall, anti-virus, etc.

 

[dwagar]

[5G is a cellular connection] - I meant 5GHz

 

[dwagar]

I have tried turning of the Windows Firewall, and tried turning off Avast Anti Virus - I have left Web Shield disabled.

 

[ColinTaylor]

Have you tried booting your PC in Safe Mode with Networking.

 

[dwagar]

that I haven't tried. I will right now. Thanks.

 

[dwagar]

Safe mode with Networking gave me the same results, 150MBPS

I'm wondering if it's a motherboard issue, I'll delve into it. It's an MSI Z270A-PRO board.

 

[dave14305]

I have a work laptop that runs Windows 10 and is loaded with "security-minded" software and agents. I can't get a speedtest over 70 Mbps on a 250Mbps ISP link, either wireless or wired. So one day after trying to tweak anything I could think of, I downloaded an Ubuntu Live CD/USB and booted the laptop from that disk and was able to get the full ISP speed.

No real help in this post other than to say that sometimes you can't polish a turd.

 

[dave14305]

Safe mode with Networking gave me the same results, 150MBPS

I'm wondering if it's a motherboard issue, I'll delve into it. It's an MSI Z270A-PRO board.

MBps or Mbps?

 

[ApexRon]

I have tried turning of the Windows Firewall, and tried turning off Avast Anti Virus - I have left Web Shield disabled.

Avast has caused me problems in past. Temporarily, remove/uninstall Avast

 

[ApexRon]

I have a work laptop that runs Windows 10 and is loaded with "security-minded" software and agents. I can't get a speedtest over 70 Mbps on a 250Mbps ISP link, either wireless or wired. So one day after trying to tweak anything I could think of, I downloaded an Ubuntu Live CD/USB and booted the laptop from that disk and was able to get the full ISP speed.

No real help in this post other than to say that sometimes you can't polish a turd.

@dave14305 Sounds like your PC protection is suspenders and belt. Sometimes less is more. I would never tolerate a protection scheme that impacts speed.

 

[dave14305]

@dave14305 Sounds like your PC protection is suspenders and belt. Sometimes less is more. I would never tolerate a protection scheme that impacts speed.

I like to think of it as ball and chain.

 

[dave14305]

@dwagar Have you ever modified Windows registry settings for Meltdown/Spectre? Perhaps a test disabling the Meltdown protections might help. The least confusing way to do that is to use Steve Gibson's Inspectre tool. https://www.grc.com/inspectre.htm

Disable Meltdown protections, reboot, and try the speedtest again. If it doesn't help, you can reverse the steps to re-enable the protections.

 

[ApexRon]

I like to think of it as ball and chain.

@dave14305 More like an anchor.