Antec SF850X SFX 850W 80+ Gold Fully Modular Power Supply (ATX 3.1, PCIe 5.1)

You're building a compact gaming rig and the last PSU you tried either rattled like a washing machine or couldn't feed a modern GPU without a daisy-chain of adapters. The Antec SF850X fits the SFX 4.1 form factor — 100 × 63.5 × 125 mm — and still pushes 850 W of clean, 80 PLUS Gold-certified power. ATX 3.1 and PCIe 5.1 12VHPWR means your RTX 4090 or RX 7900 XT gets a native single-cable feed. No adapters. No sag. Japanese capacitors, a 92 mm silent fan with Zero RPM mode, and full modular cabling so the inside of your case actually looks like you built it on purpose. Seven-year warranty. If your build is tight on space but not on wattage, this is the one

• 850 W output, 80 PLUS Gold efficiency, SFX 4.1 form factor (100 × 63.5 × 125 mm)
• ATX 3.1 / PCIe 5.1 12VHPWR native connector — no adapter needed for current-gen GPUs
• Fully modular cabling for clean builds in compact cases
• 92 mm silent fan with Zero RPM Manager for quiet idle operation
• High-quality Japanese capacitors and CircuitShield™ full protection suite (OCP, OVP, UVP, SCP, OPP, OTP, SIP, NLO)
• 7-year warranty