Power Supply
Converts wall power into the clean, stable power every other component depends on.
What is it?
The power supply unit (PSU) converts AC power from the wall into the various DC voltages components need, and delivers it cleanly and reliably.
What does it do?
It powers every component in the system simultaneously, with enough headroom to handle momentary power spikes from the CPU and GPU under load.
Wattage
The maximum continuous power the unit can safely deliver. Real-world draw should sit comfortably below this, leaving headroom for transient spikes.
Efficiency rating
80+ Bronze/Gold/Platinum ratings indicate how much input power is wasted as heat rather than delivered as usable output — higher ratings mean less waste and often better build quality.
Modularity
Modular PSUs let you attach only the cables you need, improving airflow and cable management versus fixed-cable units.
Wattage
Must comfortably exceed your system's combined power draw, with headroom for spikes.
Efficiency
Higher ratings reduce wasted heat and often indicate better internal components.
Modularity
Affects cable clutter and airflow, especially in smaller cases.
An undersized or low-quality power supply is one of the few components that can cause instability, random shutdowns, or in rare cases damage other hardware.
A properly sized PSU doesn't add performance, but an undersized one can cause a system to throttle or crash under peak load — especially with modern GPUs' power spikes.
Common mistakes
- Sizing the PSU to the average draw instead of the peak/transient draw.
- Buying the cheapest available unit for a high-end GPU build.
- Ignoring form factor requirements in small-form-factor cases.
How to choose
- Add up your components' rated power draw and leave meaningful headroom — don't cut it close.
- Prioritize a reputable efficiency rating over raw wattage alone.
- Choose modular cabling for easier builds and better airflow in compact cases.
See Power Supply products and pricing, or get a build recommended.