Can the old power supply be used with the new computer?

Let’s face it, most of us always try to reduce the financial costs when building a new computer due to the soaring prices of components and hardware, which is mainly a result of the difference in local currencies and high customs taxes on goods compared to official prices. So, in one way or another, we should examine the old computer to see if we can find some components that are suitable for use in the new computer. For example, there are many cables, sound cards, optical drives, or even power supplies, all of which are components that may help us reduce the high costs.

For some unknown reason, power supplies specifically are priced exorbitantly and excessively, perhaps due to intense market demand, especially for high-quality certified types. Fortunately, your old power supply may be sufficient for the new computer, but let’s first see what you need to know about the power supply before confirming its suitability for the new computer.

How to Remove the Old Power Supply

Before we delve too deeply into the subject, let’s talk to new users who have not dealt with hardware before. The power supply, also known as the PSU, is supposed to be located at the bottom of the computer case and connected with four screws on the back grid of the case.

If you have an OEM computer case from overseas, the power supply may be at the top of the case. To remove the power supply, after completely isolating the electricity from the wall socket, you should first disconnect all the cables connected to the components, then arrange and organize them to make it easier for you to pull out the power supply in the end.

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You will find that the power cables supplied for storage drives need to be removed, the 24-pin cable responsible for passing power to the motherboard needs to be removed carefully, the 4-pin/8-pin cable responsible for passing power to the CPU is located exactly above the CPU and needs to be removed with extreme caution, make sure in the end that all cables are insulated from the components. Then try to gather all the cables, tie them in one strip, secure them well, and leave them next to the power supply to make it easier for you to pull out the supply from the case easily after removing the screws.

Know Everything About Your Power Supply

All power supplies are supposed to have a side label indicating many values, including the extracted voltage, or as you will find it listed under Maximum Load/DC Output. But you should know that these values are not true or effective with Chinese and Korean power supplies. This means that we are talking here about power supplies certified with the Bronze certificate or power supplies that have at least an 80Plus standard or those that come out of OEM factories for integrated and ready-made devices such as Dell, hp, Acer, Compaq, Lenovo, and other such specialized companies.

The reason for trusting computer hardware manufacturers is that they often rely on large and well-known factories in producing high-quality, efficient power supplies capable of working with business servers 7/24 without interruption. Chinese power supplies are not safe even if they can power your next device, they not only produce incorrect and unstable currents but also lack the necessary protection and safety measures to maintain computer components.

These power supplies may not even be able to protect themselves, or they may have an incredible ability to protect themselves but do not protect other components. In that case, your only choice is to buy a certified power supply, or at least buy a power supply from devices imported from abroad because they are guaranteed, sufficient, and trustworthy, but first make sure that the power level will suit your future components. If you are unsure about the quality of your power supply, continue reading.

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You will find a row of values in front of DC Output on the side label on the power supply, which indicates the output voltage for each of the 12v+, 5V+, and 3.3V+ circuits – note: these three circuits are the most important values that should not exceed a noise ratio of 5% during computer operation in all states of load and idle. In other words, if you run the Aida64 program now, the 12V+ current value should be between 11.400v at a minimum and 12.600v at a maximum, and if you find that it is at 11.350v, for example, or 12.650v, you are not safe, and all your components are at risk, especially those that derive power from the +12V current (specifically the graphics card).

Returning to our discussion, if you plan to buy a graphics card for gaming, you should pay attention to the row at the bottom of the 12V+ circle with amperage value not less than 30A. This means that this circle is capable of supplying the graphics card with 360 watts, which is a decent ratio for economical and mid-range graphics cards. You may find that the 12V+ circle is divided into halves or more, which is no problem at all, although it is always best to be inside a single rail or as we call it Single Rail. But if you discover that your supply is Multi Rails, collect the amperage in all 12V+ slots, then multiply it by 12. If you find that the wattage output is sufficient for the graphics card, you are in total safety.

As for the 3.3V+ and 5V+ circuits, the same logic applies to them exactly, they should not exceed the electric noise ratio by 5% downward and upward, meaning that the 5V+ circuit can be in Aida64 program at 4.750V at a minimum or 5.250V at a maximum. The same applies to the 3.3V+ circuit. The closer the results are to the voltage current value of the circuit in all load and idle conditions, the more certain you are that you have a stable and problem-free power supply.

The reliability of your power supply depends on one thing and one thing only: the manufacturer of the supply. So, look at the side label on the power supply to know the manufacturer, then search for the name online. If you find that it is not well-known and there is no prominent brand associated with it, then you are forced to purchase a new power supply. Unfortunately, low-quality Chinese power supplies, or more accurately low-quality supplies, cannot be relied upon and cannot deliver the power written on their label. You may find on the label that the power supply is 800W or 1000W, but in reality, it may not be able to pass a real current exceeding 350W or 400W, and sometimes much less.

There is also a good way to know if this supply is good or not, which is to simply hold it in your hands. If you find that it is light, it means it is of low quality, but if it is heavy, it means it has the necessary components to generate sufficient power for computer components. Some hardware companies manufacture professional power supplies, or more accurately, they do not manufacture power supplies from scratch, but they rely on large factories specialized in power production, and then hardware companies add their logo to the power supply in the end.

For example, companies like Corsair, EVGA, CoolerMaster, NZXT, Fractal Design, BeQuiet, XFX, Antec, Thermaltake, Silverstone, and OCZ do not manufacture power supplies, but they partner with the largest power factories to produce professional supplies under their brand. Some of the biggest of these factories are Seasonic, Super Flower, FSP, CWT, HEC, Enhance, High Power, and others. If you are willing to sacrifice to buy a professional power supply that is worth all the money you will pay for it, make sure that your power supply is manufactured by Seasonic or Super Flower, but this does not diminish the importance of the other factories at all. The quality of each power unit depends on the quality of engineering and components it contains, and the level of efficiency and the extent to which it contains all the necessary components to protect itself and the rest of the computer components from risks and electrical errors. This point is specifically important for overclocking enthusiasts.

As for OEM power supplies, they are also good, but remember that the new motherboard, CPU, and GPU will put them to a real test, so first make sure of their efficiency and their ability to provide these components with clean and stable power because it will be completely different from the old components.

Are the Cables Compatible with the Future Components?

Some old power supplies inside complete devices may have a 20-pin cable instead of a 24-pin cable responsible for passing power to the motherboard. Fortunately, these supplies are rare, and you may be able to install a 20-pin cable in a 24-pin motherboard and it will work without any problems, but the advice is to avoid these supplies as much as possible.

Some motherboards require two 4-pin+4-pin cables for the CPU, and your power supply may have only one 4-pin cable. In this case, you can run the CPU with one cable without any problems, but in some rare cases of use, you may face stability issues. Naturally, one 4-pin cable is able to pass 144 watts to the CPU, so it is sufficient in most cases, and you can also purchase a Molex ATX 4-pin to 8-pin conversion cable, but remember that you will not be able to overclock this CPU until you upgrade to a stronger power supply.

Read More: How to Choose a Graphics Card Compatible with the Motherboard and Power Supply

After that, the graphics card will come, and you will definitely need 12V 6-pin/8-pin PCIe cables for it. Fortunately, most modern graphics cards do not consume high proportions of power, especially economical and mid-range cards. If you have an Original power supply that does not contain any 12V 6-pin cables, all you need to do is buy a 4-pin Molex to 6-pin PCie conversion cable.

We hope that you can use the old power supply with your new device to save some money for buying other components. Just make sure of the stability of the voltage output from the voltage circuits we talked about so that you can rest assured that the power supply can handle the new components well.