The Corsair CMPSU-850AX AX850 Power Supply pushes the state of the art for reliable delivery of clean power under imperfect conditions. If you require mission-critical stability or you simply want one of the best power supplies available, the Corsair CMPSU-850AX AX850 Power Supply is for you. All cables detach from the power supply. During installation, this gives you the flexibility of using only the cables you need for a clean system build with optimal airflow. And, when its time to replace or upgrade your power supply, it can be removed from your system without interfering with your cabling mdash the cables stay in place and connect to your new fully-modular Corsair power supply.With 90% efficiency at 50% load, the Corsair Professional Series Gold power supply runs quieter, generates minimal excess heat, and saves you money every month. The Corsair CMPSU-850AX AX850 Power Supply earned the 80 Plus Gold seal of approval, your guarantee that youre making the right choice for smart, efficient power delivery.