PSU Compatibility With CPU (2 Things To Check)

A power supply and CPU are the two most critical components in our system, and many novice PC builders are confused about whether both these components have to be compatible or not.

In this article, I’ II go through what PSU & CPU are compatible with each other and what things you need to check on PSU and CPU before buying.

Does PSU Have To Be Compatible With The CPU?

When we pick a power supply for our CPU, we have to keep two primary factors in our mind- the first thing we have to check is whether the PSU can supply the necessary wattage for our CPU/system, and secondly, we have to check whether the Power Supply comes with the necessary P4 & EPS cables for our CPU.

Don’t get confused between both these factors; in the following text, I talk about these factors in depth-


This is the first primary thing we need to check before picking a power supply for our system and CPU.

Power supplies have different wattages, and the CPU & GPU are the two most power-hungry components inside our system.

Experienced PC builders always recommend picking the Power Supply at the end so you can easily figure out how much wattage is required.

If you pair a top-tier CPU (Intel I9-13900K) & a high-end GPU (RTX 3090 Ti) with a budget-end 500W PSU, then your system will not turn on.

Because the top tier I9-13900k is an overclockable CPU that consumes 253W at maximum load, and the RTX 3090 Ti consumes 450W power. Combining the CPU & GPU will consume (253+450)= 703W of power.

There are other components too that require additional power, that’s why the 500W PSU is insufficient for this top-tier CPU-based PC build.

So, it is highly recommended to check the wattage requirement of your entire PC and then pick the Power Supply.

P4 & EPS CPU Cables

Early CPUs doesnt require a lot of power, but as time and technology progressed, power-hungry CPUs came out in the market, and to provide power for these CPUs, the power supply manufacturers introduced these P4 & EPS cables.

These cables are primarily used to provide power to our CPU socket.

Based on the requirement of CPU power, your motherboard will accept one 4-pin, one 8-pin, or both or multiple 8-pin connectors.

So, check your CPU socket & motherboard chipset type to ensure how many P4 and EPS cables your system requires, and based on that requirement, you have to choose your power supply.

These are the two primary factors that you need to check about the power supply. Below, I thoroughly explained how you could buy a compatible PSU by checking the above factors.

How To Know If PSU Is Compatible With CPU Or Not?

As I said, you have to check two primary power supply factors to make it compatible with your CPU or System. Now, let’s see how to check both the power supply factors-

Checking The Wattage

CPU & GPU are the two most power-hungry components inside your system, but other components also require power from the PSU, like-(The motherboard, SSD, HDD, Sys Fans, and RAMs).

Generally, CPUs consume power between 65W to 253W depending on their specifications, and you have to check the TDP for your CPU.

After checking the TDP of the CPU, you have to calculate the power requirement of your GPU and other components, and based on the overall power requirement, you can decide what PSU wattage your system will require.

Go to the PCPartsPicker website and choose all your components, including the CPU and GPU, to check the power requirement of your entire system.

This website will tell you what PSU wattage your CPU or system will need. Always buy a PSU with a little extra wattage by considering the future upgrade factor.

Check PSU Cables For CPU

The power supplies have a 4-pin P4 connector and an 8-pin EPS connector to supply power to the CPU socket. But what type of connector your CPU will need depends on the motherboard specifications.

Let’s understand this by taking an example-

The intel I9-13900K processor requires 253W power, and it can be compatible with several chipsets motherboards, including- Z790, Z690, B660, H670, H610, Z590, and more.

Now if we pair the I9-13900K CPU with the gigabyte Z690 Gaming X motherboard, then we need one 4-pin and one 8-pin CPU cable from the Power Supply.

The Power Supply with just a single 4-pin or a single 8-pin connector will not work with this Gigabyte Z690 Gaming X motherboard and Intel I9-13900K processor.

That’s why you have to check what chipset motherboard your CPU will support, and by checking the motherboard’s specifications, you can decide how many cables your CPU need and what power supply you have to pick.

This is how you can determine what power supply will be compatible with your CPU by considering these two factors.

Components Need To Be Compatible With PSU

Besides the Power Supply and CPU compatibility, you have to check some other compatible factors of power supplies.

A Power Supply needs to be compatible with the graphics card. Check your GPU power and PCIe cable requirements, and then pick the Power Supply. Read this complete guide- The Compatibility factor between your graphics card & Power Supply.

Furthermore, a power supply has different form factors like ATX, SFX, etc. The big-size ATX power supplies will not fit inside small PC cabinets; therefore, you also have to check the power supply and PC Case size compatibility.

Wrapping Up

The gist of the entire article is that you have to check two factors before picking a power supply for your CPU, whether the PSU has sufficient wattage and whether the PSU comes with the necessary P4 & EPS cables.

I hope this article is helpful for you, and if you want to know more about the Power Supply, PC case, and other PC-related things, then keep following this blog.

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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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