Using my home server as a router and firewall (webmin package), using an additional NIC. Doing a speed test causes a load of 25% on 2 out 4 cores of the i5-2500 CPU.
As recommended, using the switch function instead of routing, routerboard load is now 1% - 3%.

Thank you for your answers, I feared as much. The 1100AHx2 is not an option, as I need a SFP slot, as for the CCR1009, I will try alternative solutions before investing in an additional router. Tested the router by bridging SFP and port 5, this resulted in much better performance, alas there is no s...

Just switched from cable to fiber from 50/10 Mbps to 1 Gbps symmetrical. As I did not have a modem or router with a fiber-optic connection, I purchased a RB2011UiAS-2HnD bundled with a SFP module and patch-cable at the recommendation of the ISP. The connection from the ISP is on SFP1, the test compu...

Somewhat related question,

Can a RB2011UiAS-2HnD handle 1Gbps NAT?

I'm seeing 100% CPU load when doing about 410Mbps, with 10 Firewall rules, 6 NAT rules, no mangle, no queues
Is this a misconfiguration or a hardware limit?