Explanation
A video production workstation that will consist of two high-end GPUs will require a lot of power and a modular power supply. A modular power supply allows the technician to connect only the cables that are needed for the components, which reduces clutter and improves airflow. A 1,200W power supply should be enough to power the two GPUs and other components, but the exact wattage depends on the specifications of the GPUs and other components. A 400W external power supply is not enough to power the workstation and may not be compatible with the ATX case. Two 600W redundant power supplies are unnecessary and may not fit in the ATX case. A 1,500W uninterruptible power supply (UPS) is a device that provides backup power in case of a power outage, but it is not a replacement for a power supply unit (PSU). References:
https://www.comptia.org/blog/what-is-a-power-supply-unit