Question Ethernet keeps dropping to slow speeds ?

[MrHammers]

Hopefully this is the right category.

I'm to the point of troubleshooting where I stop reading the threads and start writing them. So you know I'm desperate.

When I turn on my PC the internet runs at about 980 down and 965 up with 1 ping as per Ookla. Within about 5 ish minutes it drops to 450 down and 9.7 up with 4 ping. If I unplug the cable and plug it back in it restarts the cycle of high > low > high > low over and over. If I restart my PC it acts the same. I've had this issue in the past with a different PC and the issue was determined to be the ethernet cable. Once that was replaced the issue was gone. This time is different.

Basically as of two nights ago my internet is completely unstable. I know this is going to sound like a Frankenstein of a system but here is a brief overview of how everything is connected.

Router > switch > switch (Same model) > PC

This issue I don't believe is with either of the switches because there are multiple other PCs connected to both and they have never had nor are currently having any internet issues.

Steps I have taken so far:

-Flushdns
-Change DNS
-Tried three cables I have and bought a new one. All Cat6.
-Checked PC updates
-Made sure BIOS was up to date
-Made sure all drivers are current and up to date specifically but not exclusively the ethernet adapter driver
-Reset the PC
-Disabled all other adapters
-Reset router
-Tested same switch ports and cables on other PCs
-Used windows troubleshooter (found no issues of course)
-Pretty much anything and everything suggested on arguably every forum site and Youtube video known to man

I am beyond tired of dealing with this and if I see one more forum that suggests its the cable I might actually dropkick this PC into oblivion.

PC specs:

MB: Asus Prime Z790-A WiFi (I know, I know)
Storage: 1TB WD HDD / 1TB WD M.2 NVME 4.0 SSD (recently new with fresh windows install because other NVME killed itself)
RAM: 32GB Corsair DDR5
GPU: Nvidia GeForce 3070 RTX (updated)
CPU: Intel i9-14900k 3200Mhz, 24 cores (updated)
LAN adapter: Intel l226-V
OS: Windows 11

My growing consensus (fear) is that the MB is just the garbage that everyone has told me it is and I'm out $350 and just 10 days past the return date.

Any and all help would be much appreciated!

 

[bill001g]

In some ways it is good you have only had your motherboard for so little time. Some that where manufactured when the z790 chipset first came out had intel ethernet chips that had major issue that could not be fully fixed with firmware updates.

More the problem with all asus boards is their insistance on bundling all that crap software. The key problem software is related to "gamer" network stuff. Any software that claims to give certain application preference or some how accelerate the traffic should be uninstalled. A very common name for this is cfosspeed. There are other names but none of this software can affect traffic outside the machine and if you have a network bottleneck inside the machine you are doing something very stupid.

Note it is not just asus and you also find software like this bundled in the bloatware on video cards.

Problems with switch, cables, ports etc you tend to get random data loss or maybe the port drops to 100mbps rather than gigabit. It does not consistently start out fast and then slow down.

This is acting more like some software is limiting you. Of course make sure there is nothing like parental controls on the router that cap the bandwidth. Although it won't help you find the actual problem if you were to boot a linux USB image you could confirm the hardware works correctly. You never really know maybe microsoft has some new "green" power save garbage buried someplace.