The Power Supply Unit is one of the most integral components of a PC, but often overlooked. Builders should think of the PSU as the beating heart of the PC because it provides energy to every component. Skimping on the PSU on a Gaming PC can have annoying consequences including PC crashes, PC turning-off at will, artifacting; all leading to poor gaming experience. Below are the important things to consider when choosing a power supply

#1 - Wattage. The amount of power required by the PC measured in Watts is the first thing to know. Thankfully, using PC partpickers build guide includes an invaluable tool to calculate the wattage you should use in your build. If the gaming PC components draws more power than the PSU can handle, it will leading to the annoying consequences stated above
PCPP - https://uk.pcpartpicker.com/list/

#2 - Rating 80PLUS an organisation defined the efficiency standards for power supplies. In a nutshell, some power drawn from the socket is lost when the PSU converts it to usable voltages for the PC components. The higher the PSU efficiency the less power lost during power conversion. As a recommendation, always buy PSU's with the 80PLUS certification. You'll typically find them in tiers -
*80PLUS Bronze - Entry level
*80PLUS Silver
*80PLUS Gold
*80PLUS Platinum
*80PLUS Titanium - Enthusiast level

#3 - Modularity -
* Direct cable - all the PSU cables are attached to the PSU housing directly...this is the cheapest option available. Cable management is harder to deal with.
* Semi-Modular - All the necessary cables come from the PSU case directly such at the ATX Power (20+4) connector, CPU (4+4) connector and PCIe(6+2) connector. Other non-essential plugs such as the Molex (4-pin) and SATA (15-pin connectors) are removable
* Modular - All cables are removable making cable management extremely easy and sleek.

cc Lana1 - The 24-pin, also known as the (20+4) connector provides power for the motherboard while the 8-pin (4+4) connector provides power directly to the CPU.

For many mid-range gaming PC's i.e. with a mid range CPU and GPU, as this are the two components that draw the most power, 450W to 550W 80PLUS certified power supply is usually enough. A budget PSU is the EVGA 500B power supply. On the enthusiast side of things, Corsair AX series, EVGA P2 series are reliable models.
As a rule of thumb set aside a budget or around 10-15% of the total cost of the PC build for the PSU. For example, if the total build cost $500, set aside $50-$75 for the PSU.

Related Post - https://www.nairaland.com/3267973/gaming-pc-what-need-know

When buying a PSU to provide power to a powerful graphics card look out for the current available on the 12V rail, it should also state the total power available in watts. This is important, higher is better.

Where can i buy 1300 W PSU in Nigeria?

d4gmail:
Where can i buy 1300 W PSU in Nigeria?

AFAIK 1300W isn't made. Common ones are 1200W or 1500W. You should try Amazon they ship to Nigeria.

AKBliv010:

AFAIK 1300W isn't made. Common ones are 1200W or 1500W. You should try Amazon they ship to Nigeria.

Can I get one of 500W?