Re: How multithreaded is networking in FreeBSD 15.1?

At 03:00 PM 8/16/2026, David Christensen wrote:

>My theory for running mixed sequential/ parallel programs is that 
>there is a speedup vs. efficiency sweet spot when the number of 
>threads is numerically equal to Amdahl's maximum speedup 
>value.  If I run the program with more threads, I will get more 
>speedup but less efficiency. If I run the program with less 
>threads, I will get less speedup but more efficiency.

David, thank you for the ideas. However, what I am asking is which 
choice of processors (more simple cores, lower clock speed vs. 
fewer fast cores, higher clock speed) will maximize the networking 
and routing performance of FreeBSD 15.1, given that we will be 
using lagg(4) heavily and IPFW as the firewall. The choice of 
hardware will depend on, among other things, how well 
multithreading works within the network stack and whether the 
threads are likely to get in one another's way. In older versions 
of FreeBSD it paid to use fewer, faster CPUs to avoid contention; 
I'm not sure if that's still the case with the latest kernel.

>All that said, have you considered FreeNAS (now TrueNAS)?

We're not interested in a "canned" solution. We want to handcraft 
these routers for the purpose, building them from the ground up on 
standard releases of FreeBSD.

--Brett