How to choose the power supply rating suitably??

During product development, power supplies are often overlooked, but it’s a critical piece to power on the system, and using the wrong one could be costly and causes unexpected problems during usage.

How Many Watts?

When selecting the power supply, one of the most common questions asked is, “How many watts is enough?” The answer varies widely depending on the unique needs of your system, or if you are designing a system that requires electrical power in a sustained period based demand, you must then select a higher power rating power supply to support the peak power when the electricity is in high demand. Generally, more complex systems require more power to run.

As a general rule, it’s better on the side of higher wattage rather than trying to match your needs exactly. If you’ve calculated that your system is going to use 650 watts (a common number for a straightforward gaming build), choosing a PSU with 780 or 800-watt output could be a good option, as it will give you some overhead to work with, and also allow for potential future upgrades.

Keep this in mind when considering higher wattage PSUs: a 800-watt power supply does not consume 800 watts by default. Let say, if your system is drawing 800 watts, your power supply will supply 800 watts, regardless of maximum capable output. Higher wattage output doesn’t necessarily mean more energy consumed; it means it has the ability to provide more power if your system demands it. Meaning that, if there’s no real advantage having a vastly overpowered PSU if your system doesn’t need it, you might be better served selecting a feature-rich, high-efficiency PSU that is closer to the wattage you require.

Continuous & Peak Power

You’ll also need to consider the continuous power versus the peak power capabilities of your new PSU. Peak power is the maximum amount of power the PSU can output for short periods of time, whereas continuous power refers to the amount of power the PSU is designed to output on a regular basis. Peak power is usually reached when pushing your system to its limits, like when you’re running demanding games or performing hardware benchmarks.

If there is a sudden demand for more power, your PSU should be able to handle the higher output briefly, but should not be expected to run at those higher wattages continuously. Always make sure the PSU you purchase has sufficiently high continuous power output, and don’t choose solely by peak power capabilities to ensure the system could operate contiguously & stably.