Power Supplies

A power supply is chosen on wattage headroom, connector support, and form factor — efficiency rating and warranty follow. Size the wattage to your GPU and CPU with margin for transients: the 650-850W units (Thermaltake Smart BM3 650W, ASUS TUF 850W Gold, Seasonic Focus V3 GX-850, Super Flower Leadex VII 850W) suit mainstream builds, while 1000-1200W models (be quiet! Dark Power 13, Corsair RM1000x and HX1200i, NZXT C1200) cover high-end GPUs and overclocked CPUs. Modern cards increasingly want a native 12V-2x6 / PCIe 5.x connector, so check that the unit supplies it rather than relying on adapters.

Form factor is the other fork: the SFX units (Corsair SF1000, SF750, Cooler Master V850 SFX) exist for small-form-factor cases and shouldn't be bought for a full tower where ATX is cheaper per watt. Efficiency tiers (Bronze through Titanium) mostly affect heat and electricity over time, not whether the build runs — the BM3 650W Bronze is the budget entry, with Platinum and Titanium at the top.

Start by adding up your GPU and CPU draw and leaving headroom, then confirm two things: does it fit your case form factor, and does it have the GPU connector your card needs. Buy quality over peak wattage you'll never use. Scores are based on sourced specs, not hands-on testing.