PSU Guide

The PSU (Power Supply Unit) converts AC power from your wall outlet into the DC power your computer components need. It is one of the most important components in your build -- a bad PSU can damage other components, cause instability, or even be a fire hazard. Never cheap out on your PSU. A quality power supply protects your investment in the rest of your components and can last through multiple build upgrades.

To calculate the wattage you need, add up the TDP of your major components and add a 20-25% safety margin: - CPU TDP: Check your processor's specs (e.g., 65W for Ryzen 5 5600X, 120W for Ryzen 7 7800X3D). - GPU TDP: Often the biggest power draw (e.g., 115W for RTX 4060, 220W for RTX 4070 Super, 285W for RTX 4070 Ti Super). - Motherboard: ~50-75W baseline. - RAM: ~5W per module. - Storage: ~5-10W per drive. - Fans and cooling: ~5-10W each. Example calculation for a Ryzen 7 7800X3D + RTX 4070 Super build: 120W + 220W + 75W + 10W + 10W + 10W = 445W raw. With 25% headroom: 445 x 1.25 = ~556W. A 650W PSU works, but a 750W gives comfortable room. General guidelines: - Budget builds (Ryzen 5 5600X + RTX 4060): 550-650W. - Mid-range (Ryzen 7 7800X3D + RTX 4070 Super): 650-750W. - High-end (i7-14700K + RTX 4070 Ti Super): 750-850W. - Enthusiast (RTX 4090 systems): 850-1000W.

The 80 Plus certification system rates how efficiently a PSU converts AC to DC power. The rating tells you the percentage of input power that becomes usable DC power (the rest is wasted as heat): - 80 Plus (Standard/White): At least 80% efficient at 20%, 50%, and 100% load. The bare minimum acceptable standard. - 80 Plus Bronze: 82-85% efficient. The best value tier. A Bronze-rated PSU wastes about 15-18% of power as heat. Perfectly adequate for most builds. - 80 Plus Silver: 85-88% efficient. Less common, sits between Bronze and Gold. - 80 Plus Gold: 87-90% efficient. The recommended tier for mid-range and high-end builds. Wastes only 10-13% as heat, which means lower electricity bills and less heat output. Most quality PSUs from Corsair, be quiet!, Seasonic, and EVGA offer Gold-rated units. - 80 Plus Platinum: 90-92% efficient. Excellent for systems that run 24/7 or high-power enthusiast builds. The extra cost is justified by lower power bills over time. - 80 Plus Titanium: 92-94% efficient. The highest tier. Only makes financial sense for server/workstation use or extreme enthusiast builds. For most builders, 80 Plus Gold offers the best balance of efficiency and price. Going from Bronze to Gold typically saves 10-20 watts of wasted heat, which adds up over years of use.

PSU modularity refers to how cables are attached to the unit: Non-Modular: All cables are permanently attached to the PSU. This means you will have unused cables stuffed in your case even if you do not need them. This is the cheapest option but makes cable management messy and can restrict airflow. Semi-Modular: Essential cables (24-pin motherboard, 8-pin CPU) are permanently attached, while peripheral cables (SATA, PCIe, Molex) are detachable. A good middle ground -- you keep the cables you need and leave out the rest. This is the best value option for most builders. Fully Modular: All cables are detachable, including the motherboard and CPU power cables. This gives you maximum flexibility, cleaner cable management, and the ability to use custom cable kits for aesthetics. The premium choice. For builders who care about clean aesthetics and easy cable management, fully modular PSUs are worth the extra cost. If you are on a budget, semi-modular is the sweet spot. Avoid non-modular PSUs if possible in modern builds -- the cable clutter is not worth the small savings.

ATX 3.0 is the latest PSU standard, designed for modern GPUs that draw high power through a single cable. It introduces the 12VHPWR (or 12V-2x6) connector, which can deliver up to 600W through a single cable. NVIDIA RTX 4000 series cards use this connector. If your PSU does not have a native 12VHPWR cable, you will need an adapter (usually included with the GPU). Native ATX 3.0 PSUs are cleaner and avoid the adapter, which has been associated with occasional melting issues when not properly seated. If buying a new PSU today, choosing an ATX 3.0 model future-proofs your build for current and upcoming GPUs.

A quality PSU includes multiple protection features: - OVP (Over Voltage Protection): Shuts down if voltage exceeds safe levels. - UVP (Under Voltage Protection): Shuts down if voltage drops too low. - OCP (Over Current Protection): Prevents excessive current on any rail. - OPP (Over Power Protection): Shuts down if total power draw exceeds the rating. - SCP (Short Circuit Protection): Immediate shutdown on short circuit. - OTP (Over Temperature Protection): Shuts down if internal temps get too high. Reputable brands like Corsair (RM/RMx series), be quiet! (Pure Power, Dark Power), Seasonic (Focus), and EVGA (SuperNOVA) include all these protections. Avoid no-name PSUs that skip safety features -- they can damage your components.

Budget (550-650W Bronze): EVGA 600 BR or Corsair CV650 -- reliable options around 8,000-10,000 DA. Mid-range (650-750W Gold): be quiet! Pure Power 12 M 650W or Corsair RM750e -- great value for quality builds at 16,000-22,000 DA. High-end (850W Gold): Corsair RM850x -- excellent for RTX 4070 Super or higher, fully modular, quiet operation. Around 21,000-25,000 DA. Buy more wattage than you currently need. It gives you upgrade headroom and keeps the PSU running in its most efficient load range (typically 50-70% of rated capacity).