Power

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The power supply unit (PSU) of a system determines the maximum power available to a system. These are typically selected by the vendor, based on the system configuration.

Vendors usually have a tools that will give estimates of the total power consumption, which will be a bit higher than the aggregate Thermal Design Power (TDP) of all components.

Power supplies come in different qualities classes, based on their efficiency and component quality.

Besides the price of getting better power supplies with more supported wattage, server system typically offer the choice between single power supplies and 1+1 redundant ones.

1+1 means that if one of the power supplies fails, the other will kick in to continue to support the system. These are usually hot swappable components, which means the server can continue to run with a single power supply, while the failed one is replaced.