Choosing the right power supply - Power Supply Calculator

October 2016

The power supply of your computer depends on the wattage supplied by it. There are various power supply calculating software designed to let you get the basic understanding needed for choosing a power supply unit. The computer's hardware configuration and added components define the actual consumption of power from the power sully. The optimum power supply is the "recommended wattage". It is an average value of the peak of power used by the devices connected and hardware components. It is essential for an individual to establish the power supply needed when building a PC in order to avoid future problems such as unsteadiness, random or sudden shutdown issues.

Choosing the right power supply - Power Supply Calculator

Choosing the right power supply

When building up your PC it is quite difficult to determine the power supply to be used (based on the components and the configuration used).

A simple calculation method

Here's a simple and effective calculation method (Thanks to GreyPearl).
Max Consumption CPU + Max Consumption GPU x 2
In the case of a gamer PC (i5 4430, GTX 760).
The maximum power consumption of the i5 4430 is 80W and the GTX 760 is 170W.
80 + 170 * 2
=80 + 340

A power supply of 420W (minimum) is recommended for this configuration.
A 500W power supply will be perfect and will leave enough room for overclocking.
By multiplying the maximum consumption of the graphics card by two, one hand compensates for the consumption of other components and also leaves a margin of safety.
This method is effective for simple configuration, however it does not work when the PC is equipped with multiple graphics cards!

The power consumption of the various components:

The Graphics card and CPU requires the most power. Check for the requirements on the manufacturer's website.
  • PCI-E: 5 to 10 Watts.
  • PCI (sound card): 15 Watts.
  • DVD/Blu-ray: 10 to 25 Watts.
  • Hard drive (7200 rpm): 10 to 20 Watts.
  • Hard drive (10000 rpm): 10-40 Watts.
  • SSD: Consumes very little power 0.03 - 3 Watts.
  • Tower Fan: 3 Watts.
  • CPU Fan: 3 Watts.
  • Motherboard: 20-40 watts.
  • RAM: 10 watts per module
  • LAN card: 5 Watts.

Power supply wattage calculators

Asus offers a calculator, allowing you to determine the wattage required to power up the components of your PC.

Here's an example:


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