I just set up a new router and ran some tests. I'm pretty sure it's my computer now. My connection has been slow—up to 900 ago it was fast, but now it's barely 650 Mbps max, with an average of 425 Mbps down and 360 Mbps up. Turning off antivirus and firewalls didn't really help much. The network test took a lot of CPU power. Could be the cheap build or something built by the manufacturer.
Sorry, I don't have the exact details about the adjustments needed.
Activate jumbo frames and related features. Experiment freely to ensure proper functionality across your network. Adjust parameters and observe the outcomes. Jumbo frames typically lower CPU consumption. Consider capturing the initial settings beforehand to confirm baseline behavior.