Stopping the Cardinal Sin of Colocation Rack Power Sizing

In 2024, many organizations continue to improperly size power requirements for colocation racks, relying on outdated methods that use power supply wattage instead of actual power consumption. This practice leads to significant overprovisioning, where companies pay for more power than they actually use. For instance, a typical 208V 30A rack can theoretically provide up to 5kW, but modern servers often operate at much lower power levels, sometimes only utilizing a fraction of their power supply capacity.

The article highlights examples, such as a Supermicro server that, despite having power supplies rated for 1.2kW, only consumes around 750W even under stress tests. This results in unnecessary costs, as organizations may end up paying for 4kW to 16kW of unused power. The trend is particularly pronounced in AI servers, which can have substantial power supply capacities but often do not operate at full load.

To optimize costs, it is recommended that organizations assess their actual power usage rather than relying on maximum power supply ratings. This approach can lead to significant savings and better power management, especially as high-power servers become more common. The article calls for a shift in mindset to avoid the "cardinal sin" of colocation rack power sizing, advocating for a more accurate assessment of power needs to reduce unnecessary expenses.