How a Single NIC Setting Slashed My 10GbE Speed from 7 Gbps to 300 Mbps
Debugging my new network, when 10 Gigabit Ethernet Runs at 300 Megabits
Scott Hanselman's 10GbE home network was crawling at 300 Mbps. After ruling out the NAS, disks, and SMB, he used iperf3 to isolate the problem to his Windows desktop's Intel E610-XT2 NIC. The culprit: Large Send Offload V2 (IPv4). Disabling it boosted throughput from 313 Mbit/s to 7.03 Gbit/s—a 22x improvement. He shares the debugging process and cautions that this isn't universal advice, but a reminder to measure before tweaking.
313 Mbit/sec to 7.03 Gbit/sec by changing one NIC setting.
- larrik
When I was struggling to figure out why so many of my devices on my gigabit network were only getting 100 megabits, I learned that a lot more of my devices were on 10/100 ethernet than I expected. Including some recent purchases (TV's especially).
It took me a while because I assumed gigabit had been kind for far longer than it actually was in practice.
- iknowstuff
> had its receive buffers at the default 512, although it supported up to 4096. I increased them. I love an increased buffer.
Dave Täht is rolling in his grave
- tacomagick
Might also want to see: https://docs.pixeldrain.com/posts/2024-03-07_network_optimiz...
- FatherOfCurses
Is there a similar diagnostic that can be run on a Playstation 5? I generally have good download speeds on my network but it seems to take forever to install games on my PS5.
- Arainach
Awesome writeup, thanks. I wasn't aware of iperf3 as a tool. This helped me confirm that the 10GbE lines I ran a while ago are in good shape.
I didn't need to change any NIC settings, but I'm on an X540 instead of an E610-XT2