Packet loss in Windows 11

[Praemon]

Okay, this has stumped me. So I've got a relatively new PC (about 3 months old), and I've recently identified packet loss on it. The packet loss only shows on iPerfs and not MTR/pings, and results in slow download speeds when connecting to international servers (or even just JHB from CPT). Below is a summary of what I've tried and found:

• I'm using the latest motherboard (Gigabyte B760 GAMING X DDR4) and NIC (Realtek Gaming 2.5GbE Family Controller) drivers available
• Unlikely to be lack of hardware power with i7-13700KF, 64GB RAM and Mushkin MKNSSDTS1TB-D8 Tempest 1TB SSD
• Replaced cables and tried directly through ONT
• Setup local iPerf server to do testing and same packet loss
• Reset the network adapters on Windows 11
• Packet loss in iperf only happens in Windows 11 - booting into Ubuntu resolves the issue
• Turned off security virtualization/hypervisor platform

My initial thought is that it was a faulty network card, but considering the issue isn't present when booting into Ubuntu from a USB drive, I don't think that's the case. So must be some kind of Windows 11 setup or performance issue? Any thoughts on how I can resolve?

Thanks!

P.S. Please don't suggest switching to Ubuntu as the answer

 

[RonSwanson]

My money is on the windows drivers, those 2.5 Gbe Realtek NICs are relatively new. Have you tried different driver versions from Gigabyte?

 

[Praemon]

My money is on the windows drivers, those 2.5 Gbe Realtek NICs are relatively new. Have you tried different driver versions from Gigabyte?

Will give it a go, thanks. I was on an older version and when I saw an update I was hoping it would resolve it - but no change.

I also just tried disabling the security virtualization which helped a bit, but not enough.

Next up is trying in safe mode with networking (I did try that earlier but the default Windows driver for it doesn't work - so have to manually download some versions for testing that too)

 

[RonSwanson]

Well you have ruled out hardware and cabling by using Ubuntu, so it can only be OS and / or drivers.

Maybe try Windows 10?