I had a few buddies over with their PC's on the weekend and noticed really poor internet download performance while a few of us were downloading games on steam concurrently. Adding up the cumulative speeds of all downloads, we were only getting 400mb/s on a 1gb connection. I usually get full speed when it's only me downloading. I'm on 2degrees with a supplied fritzbox 7530.

First step of troubleshooting, I noticed packet loss to the router - I tried swapping out the cable I was using, and cabled myself directly to the router rather than into the switch to rule these two things out. Second, when logging into the web gui of the router I noticed really laggy performance - the pages of the UI were very slow to load. Suspecting a CPU issue, I checked the performance stats and indeed noticed 90-100% CPU usage during these group downloads.

Has anyone else experienced this? I don't think steam is p2p so I don't think it would be generating many concurrent connections. What's frustrating is that I sold a huawei spark fiber route the other day. Would have been good to try this instead to see if it's any better.

Time to buy a better router?