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Realtek PCIe GbE Family Controller limited to 100mbps

Anonymous
2024-03-21T02:51:29+00:00

the link speed of this network adaptor is limited to 100 mbps regardless of what i do; ive set the duplex to gbps speeds, im using the correct cable as ive tested it on different devices as well as via an USB adaptor that uses the Realtek USB GbE Family Controller, through which gbps speeds is achieved, i would rather not use this method currently as i require the USB port for peripherals and multiple connections from a hub that isnt externally powered just causes problems for my peripherals.

other things that have also been done, all relevant drivers are installed.

i cant figure out what the issue is

Windows for home | Windows 11 | Internet and connectivity

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  1. Anonymous
    2024-05-27T13:39:11+00:00

    I see, thank you for the clarification.

    Can you please check again the properties of your Realtek PCIe GbE Family Controller and see under Advanced tab if there are settings called "Auto Disable Gigabit" or "adaptive inter frame spacing"? If you see either of these, kindly set it to Disabled please.

    Under the Advanced tab, disable the power saving mode. My speed went up from 100 to the 750 benchmark.

    20+ people found this answer helpful.
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  2. Anonymous
    2024-06-02T10:31:04+00:00

    I am also having a similar problem. Here's what I am doing:

    Environment

    • Windows 11 home 23H2
    • HP Envy 17.3 inch Laptop PC 17-cr0000
    • HP Universal USB-C multiport hub connected to high-speed usb c port.
    • Direct connect via CAT 6 cable to SKY router which provides 1gbit speed.

    Problem

    • Use the default Microsoft Realtek USB Gbe Family Controller driver (confirmed by looking at driver 'manufacturer' in Device Manager - 'Microsoft')
    • Maximum connection speed in speedtest by OOKLA is 500mbits (my WiFi 6 is faster - via the Intel driver)!
    • Try changing all driver settings including disabling power saving and forcing connection to 1gbit full duplex (rather than auto-negotiate) and the problem remains. Still only 500mbits speed. The options the previous thread refers to ' "Auto Disable Gigabit" or "adaptive inter frame spacing"' do not exist in my driver.

    (now)

    • Download the Realtek OEM driver from the Realtek site. v 1153.15.20.327 and install (do not reboot!)
    • Maximum connection speed in speedtest by OOKLA is now 916mbits which is expected

    (However)

    • if I reboot then the speed drops to 500mbits again. The Realtek driver stills shows as by Realtek.
    • Run the realtek driver install program and tell it to repair the installation.
    • After repair the connection speed rises to 916mbits again until another reboot.

    It appears as if, at reboot, Windows is updating something in the driver infrastructure/network stack which is throttling back the Realtek driver.

    Out of interest, I bought an ANKER USB-C to ethernet cable connector. This uses the ASIX USB to Gigabit Ethernet Family Adapter driver. In this case the connection never goes above 500mbits regardless of whether I use the ASIX OEM driver or the in-built Windows driver so it appears as if ASIX use the Microsoft infrastructure driver as their default whereas Realtek are replacing this.

    So, it appears that some portion of the Windows 11 network stack is only able to work at half a megabit! I am an experienced systems programmer so I have done a lot of fault diagnosis on this.

    10+ people found this answer helpful.
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  3. Anonymous
    2024-03-21T06:25:42+00:00

    Yep it's upto gigabit speeds but my network adapter doesn't even reflect minimum speeds of 150mbps.

    I will stress that the USB GbE controller shows gigabit link speeds but the PCIe controller is 100mbps, so it is not a matter of the router, it is definitely the PCIe controller

    6 people found this answer helpful.
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  4. Anonymous
    2024-11-18T18:07:38+00:00

    I have a similar issue as Androidranger. I have ATT fiber 1000 up and 1000 down. After updating to 24H2 from 23H2 I noticed my upload is down to 500 and it's capped at 500. what's weird it's only the upload. Download is fine.

    I updated to the latest driver from RealTek but there was no change. Well the speed now jumps to 600 in upload and slows down to 500.

    There is definitely some issue with latest windows updates and how it effects realtek network cards.

    Everything is up to date in my windows.

    I tried a linux system. speeds are fine there.

    4 people found this answer helpful.
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  5. Anonymous
    2024-12-17T11:47:22+00:00

    Have you tried to disable the Green Ethernet in the Device Manager. This worked for me btw.

    3 people found this answer helpful.
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