Comment by zamadatix

I echo what the others say in that it's much more important to know what portions of your traffic are going to need to be processed by the CPU than it is to know how beefy the CPU is. E.g., just to give an example of the usual investigation process:

- The EdgeRouter 12P is ancient and had a weak CPU for even the time

- However, the EdgeRouter 12P has a good selection of hardware offloads for things like routing/NAT & even a hardware switch chip. These functions will often run at (or very near) line rate without touching the CPU much, and the latency/jitter/buffer handling will often be better than when even fast CPUs handle the traffic on other products.

- Buuuut there are oddball restrictions. E.g. on the newer 2.x or 3.x software streams (i.e. for the last ~5 years) hardware offload for VLAN tagged traffic on the switch does not work, and the CPU cannot switch a full 1G of traffic without choking (it gets close, but not quite). Also the hardware switch only covers a certain range of ports, some ports can only be routed or software bridged.

- Even then, if you add a bunch of advanced firewall inspection rules it's gonna run out of CPU. Quicker if it didn't have offloads for some of the work, but still easy to make it go from a solid full gigabit WAN NAT box to 100-200 mbps depending on what you enable. This can repeat for a lot of features, like VPN and so on.

As far as host networking (i.e. a server sending data out of its NIC rather than trying to be a network switch/router/firewall between segments) usually the CPU will be a limitation for other things before it's the limitation for sending things out the NIC. And a quality NIC (which these particular ones seem to be) can make that even more true in a similar, but less extreme, way as the switching/routing hardware offloads on the EdgeRouter. E.g. ZFS can be CPU heavy with all of the parity/encryption/deduplication features you can enable and trying to do that on top of using SFTP to transfer the data to a remote host in a single encrypted stream can stress the CPU even more... but this CPU also doesn't look like a typical bargain basement ARM CPU you'd find in cheaper Ubiquiti products and would probably do fine for what it has.