When my main router died, I used my AR750S as a replacement, using the same Ethernet cable between my cable modem and AR750S WAN port and could only get 100Mb/sec max. After a bunch of trouble shooting, I changed the Ethernet cable, and my speed increased to a little better than 500Mb/sec, so there was some issue with the old cable. I could not get the AR750S faster then that. A single MIPS based CPU has its limits.