01What the PSU does
The Power Supply Unit converts wall AC into the +12V, +5V and +3.3V DC rails the rest of the PC uses. It's the unsung hero — a cheap PSU can take down everything else when it fails.
02Sizing wattage
Add up the CPU TDP, GPU TGP and ~100 W for the rest. Add 30% headroom for transient spikes and aging. A modern gaming PC typically needs 650–850 W; high-end with RTX 4090 wants 1000 W+.
0380 PLUS efficiency
- Bronze: ~85% efficient at typical load.
- Gold: ~90% — sweet spot for most builds.
- Platinum / Titanium: 92%+ for quiet, low-heat builds.
- Higher efficiency = less heat and electricity wasted.
04Modular vs non-modular
Modular PSUs let you attach only the cables you need — cleaner builds and better airflow. Semi-modular gives essentials hard-wired.
05Protections that matter
- OCP — Over-Current Protection.
- OVP — Over-Voltage Protection.
- SCP — Short-Circuit Protection.
- OPP — Over-Power Protection.
- OTP — Over-Temperature Protection.
06Buying tips
Stick to known brands (Seasonic, Corsair, be quiet!, EVGA, Super Flower). Read tier lists. Never cheap out — a $30 PSU can destroy a $2000 build.
