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Seasonic FOCUS GX-550

Mid-Range PC Builds, Home Office, HTPC, Quiet Builds

Overview

The Seasonic FOCUS GX-550 is an 80 PLUS Gold certified 550W fully modular power supply offering premium build quality and low noise for mid-range builds, office systems, and HTPCs. Its compact 140mm depth, fully modular cabling, and 120mm FDB fan with semi-passive S3FC control keep it tidy and quiet. A single +12V rail, Active PFC + Full Bridge LLC + SR + DC to DC topology, and 100% Japanese 105°C capacitors deliver dependable power, all backed by a 10-year warranty.

Key Highlights

  • 80 PLUS Gold and Cybenetics Gold (Lambda A) certified for 90%+ efficiency at 50% load, running cooler and using less power
  • Fully modular cabling with 100% Japanese 105°C-rated capacitors for clean builds and long-term reliability
  • 120mm FDB fan with S3FC semi-passive mode that stays off at low load for near-silent operation
  • Single +12V rail design with Active PFC + Full Bridge LLC + SR + DC to DC topology provides stable, clean output
  • Compact 140mm depth and a 10-year warranty make it a dependable premium value in the 550W tier

Technical Specifications

Brand Seasonic
Model Seasonic FOCUS GX-550
Wattage 550W
Efficiency Rating 80 PLUS Gold / Cybenetics Gold (Lambda A)
Form Factor ATX
Modular Fully Modular
ATX Standard ATX 12V
Fan Size 120mm
Fan Bearing Fluid Dynamic Bearing (FDB)
Topology Active PFC + Full Bridge LLC + SR + DC to DC
Capacitors 100% Japanese electrolytic (105°C rated)
AC Input 100-240V ~ 5A 50/60Hz
+12V Rail Single +12V Rail (45.8A)
Protection OPP / OVP / UVP / OCP / OTP / SCP
Connectors 1x 24-pin ATX, 1x 4+4-pin CPU/EPS, 2x PCIe 6+2, 5x SATA, 3x Molex
Dimensions 140 x 150 x 86 mm (W x L x H)
Weight ~1.35 kg
MTBF 100,000 Hours
Warranty 10 Years