I use same HW and cabling setup, but then with an RPi4-8GB. My fiber is PtP Gbit link, but subscription is capped to 350 (bit more because they don't want customers to complain that actual speed is lower than paid for). So I get 421Mbps both up and down in Ookla. Load on Pi4 is about 50% during the test. Note that it is not directly on the Pi4 but in a KVM 2 cores 768M allocated. There also 4 other KVMs on that Pi4, it all keeps running. Although I have several dual RJ45 boards, this setup allows moving 'router' between computers ( e.g. ARM <> Intel) without touching cables.I took the plunge and bought a Pi 5 to test its routing performance. If it was disappointing, I had 15 days to return it to the shop.
Here’s the setup:
homenetwork.png
The fiber connection is 1 Gbps.
Speedtest results:Even with limited NIC offloading capabilities, the Pi 5 performed quite well! So, I’ve decided to keep it as my router.Code:
Idle Latency: 1.47 ms (jitter: 0.02ms, low: 1.44ms, high: 1.50ms) Download: 923.27 Mbps (data used: 426.9 MB) 2.44 ms (jitter: 0.25ms, low: 1.74ms, high: 2.97ms) Upload: 895.30 Mbps (data used: 402.8 MB) 3.51 ms (jitter: 0.12ms, low: 2.13ms, high: 3.94ms) Packet Loss: 0.0%
Once I get a second computer, I'll place it on a separate VLAN and use iperf3 to measure the throughput between the two machines, routing the traffic through the Pi 5. This setup will let me accurately assess the Pi 5's routing performance by eliminating the internet connection as a variable.
Offloading does not make much sense as VLAN is just changing a byte or so in a packet. Once the packet is gone from wires to internal modern SoC, it is 100 MB/s (1Gbit/s) v.s. 20GB/s RAM/cache speed, so easy to handle. You also avoid finding a person who wants to implement complex offloading.
Statistics: Posted by redvli — Mon Jul 21, 2025 1:57 pm