Look for the number. That is the power the CPU and GPU actually use. If a PSU says 600W total but only provides 300W on the +12V rail, throw it away. Stick to brands like Corsair, EVGA, Seasonic, and be quiet! The Bottom Line Calculate your wattage before you buy the power supply.
You’ve just picked out that shiny new graphics card or a blazing-fast CPU. But before you click "buy," there’s a silent killer of PC builds lurking in the checkout cart: The Power Supply Unit (PSU).
Take 3 minutes. Use PCPartPicker. Add 30-50% headroom. Buy a reputable brand.
Your PC will run quieter, crash less, and be ready for future upgrades. And honestly? Sleeping well knowing your house isn't going to trip a breaker is worth the extra $20.
The secret sauce is simple:
Buy one that’s too weak, and your PC will randomly shut down (or worse, fry components). Buy one that’s overkill, and you’ve just wasted $100 on electricity and unneeded wattage.