Master/slave switch 'deluxe':

Many PCs have a switched mains outlet that enables your computer and monitor to be switched on at the same time. However, because it is not designed to supply high currents, this outlet should not be used to switch on too many peripherals. If you want to use the on/off switch on your PC to power up the whole computer workstation, you should use a so-called master/slave switch. Unfortunately, most commercial models and kits offer poor performance when switchmode power supplies are hooked up as the master equipment.