Question Differing Internet Speeds for Wired Devices

rmiller1959

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We just had a 300 mbps Internet service installed in our home, and my desktop routinely registers average speeds of 315 mbps. Needless to say, I'm very pleased.

My wife and son, however, have their desktops connected to the same router via Cat 6A Ethernet cables, as I do, and their average speeds are 1/3 of mine. I disconnected their desktops and plugged their cables into a laptop to do some troubleshooting, and the laptop achieves over 300 mbps, so I know the cables aren't the cause.

Is it possible that their integrated NICs are not as capable? They both claim to be gigabit Ethernet NICs, and RealTek is the manufacturer for all the desktop NICs in use in our household. I'm trying to eliminate all options before I simply revert to upgrading their motherboards or buying a standalone NIC if they still make such a thing. I'd appreciate your help!
 
There have being a couple of similar threads, and unfortunately none of them resulted in a definite solution - or some kind of usable answer.

I beleive on case resulted in nothing, but concluded that the network card was to blame (just as you have in this case).

Second case - the user experienced that the network card suddenly start worked by itself with no further explanation.

I cannot recall by now if the users actually tried to run the machines on Linux to see if it is a Windows issue or not. So I suggest you try using a Ubuntu, Mint, Manjaro, or whatever distro to test the network connection on something else than Windows - then it should at least provide an answer if it is a Windows setting or not.

That said - I do not know if Windows by NIC drivers are able to permanently change some of the NIC's settings (aka - does some of the nic settins being stored in nic/bios permanently) - So that is something that someone else have to answer.

Can you tell the motherboard/laptop models AND the name/vendor/model of the network cars that are affected?
 

rmiller1959

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There have being a couple of similar threads, and unfortunately none of them resulted in a definite solution - or some kind of usable answer.

I beleive on case resulted in nothing, but concluded that the network card was to blame (just as you have in this case).

Second case - the user experienced that the network card suddenly start worked by itself with no further explanation.

I cannot recall by now if the users actually tried to run the machines on Linux to see if it is a Windows issue or not. So I suggest you try using a Ubuntu, Mint, Manjaro, or whatever distro to test the network connection on something else than Windows - then it should at least provide an answer if it is a Windows setting or not.

That said - I do not know if Windows by NIC drivers are able to permanently change some of the NIC's settings (aka - does some of the nic settins being stored in nic/bios permanently) - So that is something that someone else have to answer.

Can you tell the motherboard/laptop models AND the name/vendor/model of the network cars that are affected?

Sure! Here is the relevant information:
  • All the machines are using Windows 10 64-bit (one is Pro, the rest are Home)
  • The motherboard/chipsets/LAN Controllers/(Download/Upload speed in mbps) are:
    • ASUS Z170-P/Intel Z170/Realtek® RTL8111H, 1 x Gigabit LAN Controller (319.90/21.43)
    • ASUS A88x-Pro/AMD A88X/Realtek® RTL8111GR, 1 x Gigabit LAN Controller (106.29/8.01)
    • ASUS P8Z77-V/Intel Z77/Intel 82579V Gigabit LAN Controller (317.29/18.45)
    • Gateway Laptop Computer/Intel HM77/Qualcomm Atheros AR8151 PCI-E Gigabit Ethernet Controller (318.04/18.86)
  • The latest drivers for all LAN controllers are installed and the BIOS is the latest available for each motherboard
  • Jumbo frames are disabled
  • Reboots have been tried multiple times
Note that the speed on the Intel HM77/Qualcomm system, a Gateway NV76R44u laptop, is 318.04 mbps download, 18.86 mbps upload, when connected to the router USING THE SAME CABLE as the one connected to the AMD/Realtek desktop that is performing at 1/3 of the speed (106.29 mbps download, 8.01 mpbs upload). That is why I've eliminated the cable, router and cable modem as potential culprits.

Ethernet cables are all Cat 6A. The router is a Netgear Orbi RBR50, and the cable modem is an ARRIS Touchstone DG3450 DOCSIS 3.1 Cable Gateway in bridge mode.
 
You need to check the speed the ports negotiate at. It is likely they are running at only 100mbps.

The most common cause of this is cable issues. It is not likely you have multiple bad ethernet ports in machines.

The problem is defective cables can work fine on some machine and not on others. It is much cheaper to buy a few different brands of cables and hope you fix this rather than replace nic cards.

You do not need cat6a cat5e will be fine at gigabit speeds. You only buy cat6a when you have 10g ports. They work in 1gbit ports but provide no advantage. The biggest thing to watch out for when you buy cables is all the fake cable on the market. The term CAT means nothing it is the EIA/TIA standards that matter so vendors lie. You need to be sure the cable you get is pure copper with wire size 22-24. All that thin or flat cable and especially the CCA cable is not certified cable and does not work consistently. Some machine tolerate out of spec cable better than others.
 

rmiller1959

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You need to check the speed the ports negotiate at. It is likely they are running at only 100mbps.

The most common cause of this is cable issues. It is not likely you have multiple bad ethernet ports in machines.

The problem is defective cables can work fine on some machine and not on others. It is much cheaper to buy a few different brands of cables and hope you fix this rather than replace nic cards.

You do not need cat6a cat5e will be fine at gigabit speeds. You only buy cat6a when you have 10g ports. They work in 1gbit ports but provide no advantage. The biggest thing to watch out for when you buy cables is all the fake cable on the market. The term CAT means nothing it is the EIA/TIA standards that matter so vendors lie. You need to be sure the cable you get is pure copper with wire size 22-24. All that thin or flat cable and especially the CCA cable is not certified cable and does not work consistently. Some machine tolerate out of spec cable better than others.

The port is set to auto-negotiate, but the result is the same even if I force it to 1 Gb full duplex. I can't imagine it's a cable issue because the same cable delivers speeds in excess of 318 mbps when connected to the laptop I mentioned previously, and I've run that test multiple times on different days and time frames. The results are consistent every time.

A master electrician installed the Cat 6a cable across my network, and the bulk cable I purchased at his recommendation meets ANSI TIA/EIA 568-C.2 standards, and is RoHS compliant and ETL listed. The cable is 100% solid bare copper and the size is 23 AWG.

In another troubleshooting step, I also connected an older Cat 6 cable to the desktop computer to see how it would perform, and the speed result is the same. I will try the older cable with the laptop tonight to see what result I get.
 
I see I missed something in the end of the post. You said you can get 106mbps this means it must be running the physical port at gigabit speed. If it was at 100mbps you would max at about 95mbits.

So we take a different approach. Many of the asus boards have gaming network accelerators I would uninstall that software if these boards have it. It tends to have lots of strange bug, at least you do not have killer chipset those are even worse.

I would next run a old line mode program called IPERF. This is a extremely simple program that will test the network part of your machine and is not affected by memory/cpu/disk etc. You need to run it on 2 of your machines in your house. I would use one you know runs at good speed. In most cases you will get over 900mbps.

If iperf runs fine then I would watch the resource monitor when transfers are running as see if there is anything that stands out. You could also try file sharing between your machines and watch the resource monitor network tab for the speeds. Be careful some of those are in BYTES/sec. This would test more of the machine. You could also download something from steam since that is not a browser based program to see if it is somehow browser related.
 

rmiller1959

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I see I missed something in the end of the post. You said you can get 106mbps this means it must be running the physical port at gigabit speed. If it was at 100mbps you would max at about 95mbits.

So we take a different approach. Many of the asus boards have gaming network accelerators I would uninstall that software if these boards have it. It tends to have lots of strange bug, at least you do not have killer chipset those are even worse.

I would next run a old line mode program called IPERF. This is a extremely simple program that will test the network part of your machine and is not affected by memory/cpu/disk etc. You need to run it on 2 of your machines in your house. I would use one you know runs at good speed. In most cases you will get over 900mbps.

If iperf runs fine then I would watch the resource monitor when transfers are running as see if there is anything that stands out. You could also try file sharing between your machines and watch the resource monitor network tab for the speeds. Be careful some of those are in BYTES/sec. This would test more of the machine. You could also download something from steam since that is not a browser based program to see if it is somehow browser related.

Thanks for the tips - I'll follow your lead! BTW, I connected another cable (Cat 6) to the same port on the router, and then to the desktop and the laptop, and ran Speedtest. I obtained the same results as with the other cable - 108.56 download/8.37 upload on the desktop, 317.66 download/9.98 upload on the laptop.
 
Try this:

Boot your computer using a Linux live-CD/DVD (or usb stick) and see is you get any noticeable speed difference. Ubuntu, Mint, etc will do just fine.

At least that will indicate if the problems is Windows/drivers related or not.
 

rmiller1959

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I thought I would close the loop with everyone on this topic. After numerous types of tests, I've narrowed it down to either 1) a problem with the AMD chipset on the motherboard or 2) a software problem. I even installed a standalone Intel gigabit Ethernet adapter using the PCI-E x 1 slot, with the same speed result. On a related note, I added another desktop computer to my network with an Intel chipset and it reaches the Internet speed levels for which I'm paying, Based on all of that, I've decided to purchase a new motherboard with an Intel chipset and processor, and see if that changes things. I'll keep you posted!
 

rmiller1959

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In case anyone is still interested, I installed a new motherboard with an Intel chipset and a Pentium Gold G5400 processor into my wife's machine today to test the theory that the AMD chipset was the limiting factor in my wired Ethernet connection's internet speed results. I did not do a clean install of Windows; I wanted to keep things as they were to determine if the new hardware would make a difference. It did - I hit 340 mbps at one point during my Speedtest trials. I don't know why the AMD chipset would inhibit the internet speed, but it appears to have been the culprit.
 
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