Not really - or perhaps, depending on what you're testing.
Traffic between different wired LAN stations is handled exclusively in the internal managed hardware switch and won't be seen by the router (and therefore can't tax it).
Routing to the internet at 80 MBit/s (and even more with SQM enabled) however will push the bthub5 to its limits. The bthub5 can do around 84 MBit/s without software flow-offloading or SQM enabled. If you enable software flow-offloading, you can usually push that towards ~110-120 MBit/s - but this clashes with SQM. Enabling SQM will require considerably more power from your router (and as a side-effect kills the benefits of software flow-offloading, so you can just as well keep it disabled), as a consequence I don't expect you to (still) achieve 80 MBit/s throughput while running SQM on this hardware (more like ~55-60 MBit/s at most).
Just for a comparison:
- VDSL2+vectoring (profile 17b), the bthub5 is only acting as ethernet router - not using its internal modem (due to wiring difficulties at the moment)
- VLAN tagging on WAN
- PPPoE running on the bthub5
- 100/ 40 MBit/s (~94/ 33 MBit/s effective throughput)
- WLAN enabled, but currently no clients connected
running a speed test will push one core to >95% (the other remains at ~30-35%, routing traffic is mostly single-threaded, leaving the second core dormant), htop is better at visualizing this than top. Actually using the VDSL modem will not change these figures that much (the modem functionality is mostly handled in hardware/ firmware), heavy WLAN traffic is rather prominent in the CPU usage as well.