I didn't say a PC couldn't; I believe that the hardware-based min-routers will outperform the PC-based solution.
My basis is the timing and buffering that must occur in a PC for standards compliance, coupled with a general-purpose operating system (even one that's "tuned up") versus a built-to-purpose device that is optimized for the function, doesn't have the standards compliance issues, and runs only on OP code (which was written to accommodate a specific purpose).
With regards to the 486: the architecture of the motherboards, pci bus (or EISA bus, or MCA bus......), the RAM/memory management system....would slow the system down even further.
The Mini-routers are switching at ~7.5 milliseconds...the routing/firewall process is a little slower, but not much.
It's pretty unlikely that a PC-Based system could read in a frame to NIC1, push it up the stack, make a routing/forwarding/firewall decision, change the frame as necessary for NAT, then push it down the stack and clock it out of NIC2 in the same time or less...especially a 486...and probably not a PIII...there's too much software in the way.
The PC could probably handle higher capacity, but it's slower....
It's gotta be....just look at the hardware and software processes involved.
FWIW
Scott
(besides, the person was asking for an opinion, I gave 'em one)