[SOLVED] Unstable Gigabit Connection

cliffflip

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Apr 9, 2010
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Hi,
I use my old PC as a Plex Media Server. The mainboard has a gigabit ethernet port (Realtek RTL8111GR) which worked with no problems until these last 3 weeks, which drops the connection to 100mbps or even 10mbps. When it's the latter (and more often happens lately), it struggles streaming high-resolution content, and I get a very low speed when I'm transferring files from other PCs through Samba. All peripherals support at least a gigabit connection (Archer C80 router, cat5e cables, and of course gigabit port on other PCs and TVs).

I have tried to change the cable but no joy. I also have installed the latest driver from the mainboard page, Windows Update, and Realtek but the problem remains. The only solution is to unplug the cable, wait at least 1 minute then replug the cable. It often ends with a 100mbps connection (amber LED light) or going back to 10mbps (no light). It's getting harder to get a 1000mbps connection these last few days. Other devices in my home network work as they should.

I can buy a gigabit PCI card but if there's any solution I can try first, or if there is anything I should know, please tell me.

The PC specs are:
  • Windows 10 Pro 20H2 19042.985
  • AMD A8-7650K
  • ASRock FM2A68M-DG3+
  • 2x8GB DDR3 Memory
  • 120GB WD Green SSD
  • 4TB WD Red HDD
  • AMD RX550 4GB GPU

Thanks in advance.
 
Solution
This sounds like a failing cable somewhere along the line (if there's jacks involved, etc), but could also be the nic. Since usb gigabit nics are pretty cheap and painless to try out, I would just try that and if it fixes it, good enough and life goes on. :)
This sounds like a failing cable somewhere along the line (if there's jacks involved, etc), but could also be the nic. Since usb gigabit nics are pretty cheap and painless to try out, I would just try that and if it fixes it, good enough and life goes on. :)
 
Solution
I agree it is likely some cable or wall jack. This is actually very common for bad ethernet. Even though ethernet passes very little power the parts still tend to very slightly increase in temperature when being used. The metal in these expand or contract with these temperature changes and sometimes on a marginal cable it is enough to affect the traffic. Unplugging it both allows the metal to cool and physically moving it may realign it if it is some issue between the plug end and the jack. But this really doesn't matter as a home user you blindly replace all the cabling in the path and then you start replacing the ports.
 
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cliffflip

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Apr 9, 2010
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Thanks for your replies.

I got the Windows 10 21H1 update not long after I posted this thread. The problem's gone after installing the update, so I guess it's a Windows bug?

I'll keep your suggestions in mind if this problem comes back. I hope not, though.