650W Or 750W PSU: Make The Right Choice For Your PC?

Many inexperienced PC builders are confused about what Power Supply wattage they should pick.

Due to this confusion, they chose the safest option and picked a PSU between 650W and 750W.

But, this is not the correct way of selecting a PSU with any random wattage. This article will thoroughly explain whether you need a 650w or 750w PSU and what is the right way of selecting PSU wattage.

Whether you need a 650W or 750W PSU that depends on what components you use inside your system (especially the graphics card).

If you are using all budget-end PC components and a mid-level GPU (RTX 2070 Super), then the 650W psu is enough for your system.

On the other hand, if you are using mid-range components with an ultra-gaming GPU (RTX 3070 TI), then you need a 750W Power Supply.

Check The Power Requirement Of Your System?

A PC includes several components inside, like the CPU, Graphics card, motherboard, peripherals, fans, etc.

These different components consume different wattages of power. However, the CPU & GPU are the two most power-hungry components.

Before making any decision about whether you need a 650W or 750W PSU, you have to check how much power your components will require.

The modern CPUs consume power between 95W to 255W, while modern power-hungry graphics cards can consume up to 450W.

You have to calculate the power consumption of all your system’s components, and then you can estimate and pick the correct PSU wattage.

To calculate the wattage requirement, you must gain a little knowledge about the components you are using.

You can see the table image below to get an estimated idea of how many watts our components generally consume.

What PC Components Use how many PSU watts

The above image clearly mentions that SSDs generally consume power up to 9W, a hard drive consumes power around 20W, RAMs consume power between 7W to 15W, and CPU fans consume power between 5W to 6W.

Use (PCPartsPicker) to determine how many PSU watts you need

Several websites in the market will give you an approximate idea about what PSU watts you need.

Among all those websites PCPartsPicker is one of the most popular sites, and many PC builders recommend this site to use.

To figure out exactly how many PSU watts you need, you have to check the power consumption of all your system components.

Let’s check how you can use this website-

Just Visit the PCPartsPicker website, and there you will get a builder option; just click on that option.


Then you will go to the Choose your parts section, where you have to choose all your PC components.

Once you choose all your PC components, this website will calculate the estimated wattage.

However, this estimated wattage is not 100% accurate but nearly 95% or more accurate.

Before purchasing a PSU for your PC, you have to check the compatibility of your PSU with your system.

Read these articles to check the PSU compatibility with GPU & PSU compatibility with CPU.


According to Wikipedia & HowToGeek.com, overclocking is the practice of increasing the clock rate of a computer to exceed that certified by the manufacturer.

Many PC users are overclocking their components like CPUs and GPUs to achieve higher processing speeds.

But overclocking not only increase the processing speed, but it also consumes higher power from the Power Supply.

So, if you plan to overclock your components, then you need to pick a PSU with higher wattage.

Generally, when we overclock, our motherboard consumes 20 to 50 watts more, the RAM consumes 2 to 3 watts more per stick, and the storage devices & system fans consume 1 to 2 watts more than usual.

So, if you plan to overclock your system, you have to pick a Power Supply with 100 watts extra.

Final Thoughts

Expert PC builders always recommend picking a power supply by calculating the required PSU wattage and by multiplying that wattage by the number 1.5.

Let’s understand this if our overall system requirement is 420 watts, then multiply 420W by 1.5 (420*1.5= 630 watts). In this case, we can pick a 650W power supply.

If our overall system’s power consumption is around 500W, we need to pick a PSU (500*1.5)= 750W power supply.

This is how following a single 1.5 multiplying formula, we can easily estimate whether we need a 650W or 750W power supply.

I hope this article is helpful for you, and if you have any questions, then join our Reddit group and ask questions.

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Hi, I'm Pallab Mitra, the founder of this blog. I'm a computer enthusiast, and I'll be sharing my knowledge and expertise about PCs on this blog. Read More- About Me 

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