Power supply unit Seasonic SRP-CGX851-A5A32SF 850 W ATX, Fully-Modular, 80 PLUS Gold, 120 mm fan, Black

The Seasonic SRP-CGX851-A5A32SF is an 850 W ATX power supply from the updated CORE GX ATX3 series, compliant with ATX 3.1 and PCIe 5.1 standards. It features an 80 PLUS Gold efficiency rating, a fully modular cable system with braided black cables, and active cooling via a 120 mm hydro dynamic bearing fan managed by Seasonic’s Smart and Silent Fan Control. The unit is designed for reliable operation across a wide range of PC builds and is covered by a 7-year worldwide manufacturer’s warranty.

Advantages

The power supply combines a high-efficiency 80 PLUS Gold design with a fully modular layout to reduce cable clutter and improve airflow. An updated PCB layout and automated surface mount production increase build consistency and reliability. Smaller MOSFETs and a redesigned heatsink free up internal space to improve heat dissipation. The Smart and Silent Fan Control balances cooling performance and noise, while reduced line resistance and lower impedance improve voltage stability under load.

Suitable for

• Gaming PCs with mid to high power requirements
• Workstations and content-creation rigs
• Custom builds that require fully modular cabling
• Systems using PCIe 5.1 components and ATX 3.1 motherboards

Key specifications

• Total output power: 850 W
• AC input voltage: 100–240 V
• AC input frequency: 50/60 Hz
• Efficiency: 80 PLUS Gold
• Form factor: ATX
• Cabling: Fully modular with braided black cables
• Cooling: Active fan, 120 mm hydro dynamic bearing
• Cooling control: Smart and Silent Fan Control
• Color: Black
• Manufacturer warranty: 7 years (worldwide)

How to use

Install the Seasonic SRP-CGX851 into a compatible ATX chassis following standard PSU installation procedures: secure the unit to the case, connect the AC input cable to mains power, and attach only the required modular cables to motherboard (24-pin, CPU), PCIe, SATA and peripheral devices. Ensure the power supply is set to the correct mains voltage range if applicable and that system grounding and case airflow are adequate. Prefer gradual system power-up and perform a functional check before sustained heavy loads.

Recommendations

Use fully modular cabling to route only necessary cables, maintain clear airflow paths in the case, and place the system in a well-ventilated environment to maximize cooling and prolong the PSU’s service life.