How to choose a good PC power supply

How to choose a good PC power supply. Currently online and computer city power supply types, models, a wide variety, see the head is big. How to choose their own suitable power supply? How to choose a new configuration desktop power supply? CPU, motherboards, hard drives, memory, graphics cards are marked with power consumption.
Such as:
B75M-D3V motherboard is about 8W
I5 CPU is about 60W
DDR3 1600 8G memory is approximately 2W
1000G hard disk is about 10W
Independent graphics card is about 10W
Total about 100W
According to the power consumption of the hardware, plus about 100W, select the power supply can be.
I chose the rated power of 350W power supply (for the future of computer hardware upgrades and other independent preparation).
How to choose the power source of the old computer upgrade hardware?
There are a lot of friends ready to upgrade computer hardware, mainly for upgrading CPU, solid-state drives, memory, graphics cards, motherboards and so on. But many friends tend to ignore the power upgrade. The following are some suggestions for friends:
Software testing (such as Lu Master) about the power consumption of computer hardware, as shown in figure. Plus 100W or so, if the power to achieve this power, you can not upgrade the power supply, otherwise we must consider the power upgrade. How to judge the size of the power supply:
Power supply estimation method: the maximum output current value of +5V multiplied by 10, equivalent to the rated power supply. Such as +5V=20A, its rated power is 200W, plus 50W, is about the power output power. As figure:
Choose a good power supply can make your computer with a smoother, better experience, computer and other computer configuration life extension. The following will introduce you to a few general good power models: A-330W, A-430W, A-530W, N-280W, N-300W.