Power Supply Calculator
Calculate the right PSU for your build
Processor
Graphics Card
Memory & Storage
Cooling & Peripherals
Power Requirements
PSU Tier Recommendations
80+ Efficiency at Load
Gold or higher recommended for gaming builds
Component Power Reference
GPU Power Consumption
CPU Power Consumption
Build Type Guidelines
Office / HTPC
Integrated graphics, low-power CPU, minimal storage
Mid-Range Gaming
RTX 4060-4070, Ryzen 5/i5, standard cooling
High-End Gaming
RTX 4080/7900XT, Ryzen 7/i7, AIO cooling
Enthusiast / Workstation
RTX 4090, i9/Ryzen 9, custom loop, multi-GPU
Frequently Asked Questions
Why do I need more wattage than my components use?
PSUs operate most efficiently at 50-80% load. Running at 100% reduces efficiency, generates more heat, and leaves no headroom for power spikes. Modern GPUs can spike 50%+ above TDP momentarily. A PSU sized 20-30% above your calculated needs handles these spikes safely while operating in its efficiency sweet spot.
Is a modular PSU worth the extra cost?
Modular PSUs let you connect only the cables you need, improving airflow and aesthetics. Fully modular units are easiest to work with; semi-modular have fixed motherboard/CPU cables but modular peripheral cables. For most builds, semi-modular offers the best value. Full modular is worth it for clean builds or frequent upgrades.
What's the difference between single and multi-rail PSUs?
Single-rail PSUs deliver all power through one 12V rail, simpler but less protected against shorts. Multi-rail splits power across several rails with individual overcurrent protection. For most users, quality single-rail PSUs are fine and often preferred for high-power GPUs. Multi-rail can trip protections if you don't balance loads correctly.
How long do PSUs typically last?
Quality PSUs last 7-10+ years. Look for units with 7-10 year warranties from reputable brands. Capacitor quality matters most for longevity. Japanese capacitors are preferred. Avoid no-name budget units that may fail early or damage components. A good PSU is worth the investment as it powers and protects your entire system.
Do I need ATX 3.0 / PCIe 5.0 for new GPUs?
ATX 3.0 PSUs include the new 12VHPWR connector for RTX 40-series GPUs and handle transient spikes better. However, adapters work fine with quality older PSUs. ATX 3.0 is nice-to-have, not essential. If buying new, ATX 3.0 future-proofs your build. If your current PSU has adequate wattage and quality, the adapter is perfectly safe.
Can I use my old PSU in a new build?
If your PSU has adequate wattage, proper connectors, and is from a reputable brand less than 5-7 years old, it's usually fine to reuse. Check that it has enough PCIe power connectors for your new GPU. Older units may lack efficiency or modern protections. When in doubt, a new quality PSU is a worthwhile investment for system stability.
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