I am building a quad core server mostly for file serving and hosting VMs. The priority for this system is energy efficiency (NO overclocking). My issue is that I own a Q6600 G0 stepping but was debating about selling it and getting a Q9400. Will I see a huge savings in electricy by switching? My understanding is that both processors draw about .85 volts idle but the Q9400 draws less power under load. Since this machine is a server, it will probably be idling 95% of the time even with multiple VMs running. The motherboard I am using is a Foxconn p45 micro-atx with ICH10R which I believe is a very energy efficient board. Any advice would be greatly appreciated.