Parts List for a Custom PC Build

The 8 Required Components

The main parts you need for a custom PC are: CPU, motherboard, RAM, SSD, PSU (power supply), case, CPU cooler, and OS. A GPU can be skipped if you choose a CPU with integrated graphics, but for gaming you'll add it as a 9th component. Total budget varies with timing and part prices, so decide on your use case first and compare several sample builds.

Fig. 1: In a standard gaming custom PC, CPU + GPU make up about 40%. The rest is shared across motherboard, RAM, SSD, PSU, and case.

Quick Role Review

CPU: the calculating brain. Motherboard: the foundation that slots all parts together. RAM: the desk where active data sits. SSD: the bookshelf storing the OS and apps. PSU: converts power and distributes it to every part. Case: the outer enclosure that determines fan layout and appearance. CPU cooler: dissipates heat (comes in air-cooled and liquid-cooled types). OS: most people choose Windows 11, but free Linux is also an option.

Build Examples by Use Case

For "study and office work," start with a CPU with integrated graphics, 16 GB RAM, and a 512 GB SSD with a comfortable PSU. For "gaming," look at the recommended specs of the games you want to play and work backward to choose the GPU and PSU wattage. For "video editing and AI image generation," RAM capacity and GPU performance have the biggest effect. Prices change, so always check current prices just before ordering.

Fig. 2: Study ¥80K → gaming ¥165K → creator ¥300K. The GPU share changes dramatically by use case.

How to Choose as a Middle or High Schooler

For your first build, narrowing down to a single use case makes choosing easier. If you're not gaming, a study build is often sufficient; if you are gaming, work backward from the recommended specs of the games you want to play. If you're interested in AI image generation or video editing, give yourself headroom on RAM and GPU. Order all parts at the same time, and wait until everything arrives before starting assembly.

Compatibility Check Order

The key to part selection isn't performance first — it's "will these parts work together?" Check in this order: CPU and motherboard socket; memory standard (DDR4 or DDR5); case and motherboard size (ATX, MicroATX, etc.); PSU wattage; CPU cooler height clearance. SSDs also differ between M.2 and SATA installation. If in doubt, have a family member, store clerk, or knowledgeable friend review your parts list before ordering.

Common Pitfalls

Common Parts-Shopping Mistakes

Forgetting to buy the OS — you finish the build and it won't boot.
Not checking whether the included CPU cooler is adequate — forgetting to order a separate one.
Buying a motherboard that doesn't fit the case — screw holes don't line up and it can't be mounted.

How Will This Knowledge Help You?

The experience of selecting parts yourself builds fundamental capability for any IT-related career. Server management, data center work, game company test-PC procurement — workplaces always need people who can "optimize performance within a budget." Having personally built a PC with your own money as a student gives you a concrete, memorable story to tell in job interviews.

Try It Today

3 Steps to Get Started

Decide on your use case (study / gaming / creative) and set a budget ceiling.
Compare three sample builds on Kakaku.com or a BTO shop.
Build a parts list spreadsheet and calculate the total cost.

Summary

A custom PC requires mainly 8 parts, and the components to prioritize change based on your use case. Study, gaming, and video editing each call for a different setup, so fix your use case and budget ceiling first. A forgotten part or compatibility mistake will stop you cold on assembly day — build your list, then order. The fun of a custom build starts from the moment you plan your first configuration.