balancer is light weight since it only forward packets between backend server and user. no need powerful hardware. the bottle neck should be NIC. one CPU should be far enough to handle a 1G NIC. for multiple NICs or 10G NIC, not sure 1 CPU is enough or not and I'm not sure how to measure it. --- this is based my reading and limited knowledge, to exchange information quickly with forum users. Welcome experts' opinions on this.