Seasonic FOCUS GX-850 850W power supply

Compact 850 W ATX power supply

The Seasonic FOCUS GX-850 delivers 850 W of continuous power in a 140 mm deep ATX form factor that fits all standard cases. Its fully modular cable set lets you connect only the leads your build requires, reducing clutter and improving airflow. The unit carries 80 PLUS Gold certification and uses premium Japanese capacitors for reliable efficiency. It is built for modern GPU platforms including RTX 30 and 40 Super series cards.

Sustained-load behaviour and cooling

A single +12 V rail rated at 70 A provides stable output during extended gaming or rendering sessions without the voltage droop seen in multi-rail designs. The 120 mm fluid-dynamic-bearing fan runs under a hybrid control scheme that offers a choice between S2FC and S3FC modes, the latter enabling a fanless state at low loads. Cybenetics Standard+ rating confirms low acoustic output across typical operating ranges. MTBF exceeds 100 000 hours, indicating long-term durability under continuous use.

Compatibility checks before ordering

Verify that your case can accommodate a 140 mm deep power supply and that the motherboard accepts a 20+4 pin main connector plus the required EPS12V cable. Count the PCIe devices you plan to power; the unit supplies six 6+2 pin connectors for graphics cards. Ensure you have enough SATA power headers for drives, as ten are provided. Confirm your mains supply falls within the 100–240 V, 50/60 Hz input range.