What is a PSU?

The Simple Version

The PSU (Power Supply Unit) converts the AC power from your wall outlet into the DC power your components need to run. It feeds electricity to your motherboard, CPU, GPU, storage drives, and fans. It's not glamorous, but a poor PSU can cause system instability, random crashes, or in rare cases, damage other components. It's not the place to cut corners.

How Many Watts Do You Need?

Add the power draw of your CPU and GPU, then add 100-150W of headroom. Budget builds with a mid-range GPU typically need 550-650W. Mid-range builds (e.g. Ryzen 5 + RTX 4070) need 650-750W. High-end gaming or rendering rigs (Ryzen 9 + RTX 4080) should have 850W or more. For music production and digital art workloads without a high-end GPU, 550-650W is usually plenty since these workflows don't push power draw the same way gaming does.

For 3D Rendering and Heavy Workloads

CPU rendering in Blender can push your CPU to 100% sustained load for hours. If you're running a powerful CPU alongside a high-end GPU simultaneously, your power draw under full render load can spike significantly. Size your PSU generously — running a PSU at 90%+ capacity continuously shortens its lifespan and can cause voltage instability. 850W+ is a safe target for dual high-end component builds.

Efficiency Ratings — The 80 Plus Scale

PSUs are rated by efficiency: 80 Plus Bronze, Silver, Gold, Platinum, and Titanium. Gold is the sweet spot for most builds — it runs efficiently, wastes less power as heat, and tends to come from reliable manufacturers. Bronze is fine for budget builds. Platinum and Titanium offer marginal efficiency gains that rarely justify the cost premium for most users.

Modular vs Non-Modular

A fully modular PSU lets you only connect the cables you need, which keeps your case tidy and improves airflow. Semi-modular keeps essential cables fixed and lets you remove extras. Non-modular has all cables permanently attached, which can create cable clutter in smaller cases. For a clean build — especially important if you work in a small or visually organized setup — modular or semi-modular is strongly recommended.

Stick to Reputable Brands

A cheap, unknown PSU is one of the few components that can physically damage the rest of your build through voltage spikes or failures. Stick to trusted brands: Corsair, Seasonic, EVGA, be quiet!, and ASUS TUF all make reliable units. Avoid suspiciously cheap options from unknown brands, especially on marketplaces with third-party sellers.

What Should I Buy?

Budget builds: Corsair CV650 (650W, 80 Plus Bronze). Most mid-range builds: Corsair RM750x or Seasonic Focus GX-750 (750W, Gold, fully modular) — this is the recommendation for the majority of users. High-end or rendering rigs: Seasonic Prime TX-850 or be quiet! Dark Power 12 (850W+, Platinum/Titanium). Spending $80-100 on a quality Gold-rated unit is one of the smartest investments in any build.