What does the second core do?

[iissmart]

Just upgraded from an AC66U to an AC3100 and this is my first experience with a dual core router. I have gigabit fiber so I can put a pretty heavy load on the router just from routing. When pegging the bandwidth by downloading something on a client computer I've noticed only the first core (Core 0) is pegged or high usage. The second core barely moves from 0%. Is this normal? I was expecting the load to be balanced between the two cores.

Random info if it helps: I don't use VPN, HW Acceleration is Enabled, CTF (cut through forwarding) is active, and I have VLAN tagging on the WAN port using IPoE (not PPPoE). I am running Merlin's firmware.

 

[L&LD]

Normal.

If you did use VPN, torrenting software on the router or other features, then the second core would be used.

 

[RMerlin]

Asus is also attuning some services to run specifically on the second CPU core.

Things like network traffic are tied to the first core, due to limitations in the Linux kernel and the Broadcom drivers.

 

[Darcy]

Funny because I have the AC66R and tried another router from a different company and it did not work out well. I'm back to the AC66R and was thinking about buying the 3100 or wait and see if the Luma is an improvement over the eero and go down the mesh routing path.

 

[sfx2000]

Asus is also attuning some services to run specifically on the second CPU core.

Things like network traffic are tied to the first core, due to limitations in the Linux kernel and the Broadcom drivers.

Some applications are pinned to a core (good example is OpenVPN), but other applications are more SMP/SMT friendly - if I recall, Transmission (TorRent) is multithreaded, so it does bounce between cores even for a single thread...