TDP (Thermal Design Power)

The maximum heat a GPU is designed to dissipate under load, measured in watts. TDP directly determines your power supply requirements and cooling needs. A 450 W GPU like the RTX 4090 needs at least an 850 W PSU and good case airflow. For quiet builds or small-form-factor AI PCs, TDP is a critical constraint that may push you toward more efficient options like Apple Silicon or lower-power GPUs.