1Gbps coming into house, but wired PC limited to 400/500Mbps

Forums › LAN (ethernet/Wifi/routers/Bluetooth) › 1Gbps coming into house, but wired PC limited to 400/500Mbps

Scoobing

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#306752 18-Aug-2023 14:03

Hi,

I have One NZ Fibre Max (900/500). I have an Asus RT-AX88U router running Merlin firmware.

Running a speedtest on the router internally (via the GUI) shows the correct speed:

However a wired cat6 connection to my PC shows 400/500 max d/l. Different times of the day, different speedtest sites. It's almost as if the PC is self-limiting the download speed without telling me why. The connection shows as 1000/1000 in the ethernet adapter.

I recently switched from Bigpipe earlier in the week but was achieving 900 or so d/l on the same PC.

Is there anything else I can look into here? I've reset the network adapter, cycled the ONT and router.

cddt

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#3117630 18-Aug-2023 14:12

Can you also try a different PC, OS, and browser to rule those three things out.

I once had an odd problem where a combination of settings to troubleshoot an earlier driver problem and a software upgrade started triggering a large number of IRQ interrupts, the only symptom of which was a significantly degraded network performance.

Scoobing

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#3117635 18-Aug-2023 14:21

Thanks for the reply, it's actually hard for me to test with another wired machine, as all other devices are wi-fi and don't have ethernet ports.

Would creating a bootable Ubuntu USB stick be worth a go?

cddt

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#3117636 18-Aug-2023 14:22

Scoobing:

Would creating a bootable Ubuntu USB stick be worth a go?

If you have the time, I would do it just to be able to say you had ruled it out.

darylblake

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#3117655 18-Aug-2023 15:05

I almost wonder if it is the web browser.

I am on hyperfibre, and doing a test in the browser uses a lot of resources. I get about ~2gbit with a browser. With the CLI I max it out.
Install the CLI tool there is one for windows now and run a test.

Scoobing

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#3117658 18-Aug-2023 15:16

Using the CLI tool helped - got the d/l up to around 650.

However I just booted Ubuntu onto the machine and tested again using firefox and that got me the expected result of 900 down 500 up.

So something in Windows is affecting things, but no obvious culprit.

darylblake

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#3117659 18-Aug-2023 15:17

What is the latency like between your windows machine and your router?

Do an MTR or a ping test. It should be sub 1ms with next to no jitter.

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Scoobing

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#3117663 18-Aug-2023 15:26

darylblake:

What is the latency like between your windows machine and your router?

Do an MTR or a ping test. It should be sub 1ms with next to no jitter.

I don't know how to look at this specifically. I can do a ping test to www.google.com from within the router, or I've also run the MTR tool on the windows machine. Will that tell me about the latency between the windows PC and the router? I am struggling to interpret the output.

darylblake

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#3117664 18-Aug-2023 15:32

Windows back-off sucks. Once you get over a few MS of latency you will lose a lot of speed. There might be retransmits happening on your LAN. This could be for a number of reasons which I cannot easily identify.

From the CLI run a ping -t IPOFROUTER

IT shouldnt be jumping around, it should stay consistantly about 1MS.

I suspect you have some app on your windows machine that is interfering with it.. it may be hard to diagnose.

Scoobing

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#3117666 18-Aug-2023 15:40

darylblake:

Windows back-off sucks. Once you get over a few MS of latency you will lose a lot of speed. There might be retransmits happening on your LAN. This could be for a number of reasons which I cannot easily identify.

From the CLI run a ping -t IPOFROUTER

IT shouldnt be jumping around, it should stay consistantly about 1MS.

I suspect you have some app on your windows machine that is interfering with it.. it may be hard to diagnose.

Ok that came back as consistent 1MS, but I think you are right about the potential cause. I'll try safe mode on Windows and then start removing some apps. Might just switch to Ubuntu full-time...

Scoobing

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#3117669 18-Aug-2023 15:45

When I changed from Bigpipe to One NZ, I had to make a few config changes in the router, Bigpipe uses PPPoE and One NZ uses Automatic IP. That's been the only change (that I have noticed) since this issue started. The WAN connection type couldn't be a factor here could it?

And Bigpipe had VLAN disabled, with One NZ they need it set to on (VLAN ID 10).

cddt

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#3117678 18-Aug-2023 16:07

Scoobing:

However I just booted Ubuntu onto the machine and tested again using firefox and that got me the expected result of 900 down 500 up.

So something in Windows is affecting things, but no obvious culprit.

Glad to hear you are zeroing in on the problem. You could reinstall Windows. I don't have any advice for troubleshooting on Windows unfortunately.

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Lias

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#3117767 18-Aug-2023 17:47

I've had multiple occasions where a driver update or changed driver version resulted in speed issues with NIC's

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Scoobing

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#3117775 18-Aug-2023 18:50

I updated my ethernet card drivers. In my case it was a Realtek PCIe GBe Family controller. This seems to have resolved the issue. Will test again a few more times over the weekend.

sqishy

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#3117949 19-Aug-2023 12:20

I suspect also sometimes you can have Parental or Access Control turned on that slows the ports down.

darylblake

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#3118040 19-Aug-2023 23:26

Yup so seem windows provided some generic driver which was not efficient at offloading. Glad you sorted it.