I don't have that much to begin with, and I know it doesnt make that much of a difference, some days it just seems like its faster with a faster cpu.
You're right
I am managing an important network, with over 400 PCs and Macs connected throught the monowall, and i have been obliged to upgrade from a Piii 1Ghz to a little Core 2 E2140, as the Piii CPU was permanently overloaded.
The original setup should have been more than enough, sounds like the NIC cards or Hardware were getting overloaded more than m0n0wall, what type of NICS were you running? Was m0n0wall running near 100% CPU all the time?
I've run a 500 PC network on a 12/2 Mbps link using nothing more than a 200 MHz PI machine with 128MB of RAM + Traffic Shaping and even at full saturation (which was frequent during peak hours), the machine was lucky to get over 30% CPU. No one ever complained about slow Internet and during full bandwidth peak, I would test with my laptop on speed sites and such and still everything was very responsive and quick.
To this day, it's still running/working without any issues (this was the old AT motherboard chassis) from 1996