Each component of the PC has a maximum consumption in load, each manufacturer is obliged to display that consumption in the technical book of the product. So, you can calculate the total load of the components and you will know which source to buy. Do not forget! Also consider the peripherals that you will connect to the PC, either through the USB ports or through any type of PC connection port.But for the most part, I will list the average consumption of the components of a PC:·         An hdd has an average consumption of 20-30w in load·         An ssd consumes about 3-10w·         The i3 processor consumes about 40-50w in load·         A gtx 1060 video card has a maximum power consumption of 100w·         Peripherals do not consume much but it is good to put about 30w to make sure that the system supports several peripherals simultaneously·         Motherboard (sound / fans / various ports etc) about 50w maximum for an average system.·         RAM, the lower the latency, the lower the power consumption, but on average about 15w consumes a normal load on the load.It is difficult to calculate precisely for each system, but on average these are about the consumption of a decent system. A 450w-500w source should be sufficient for a gtx 1060 video card system.