The Thermal Design Power (TDP) is the maximum power dissipation in watts that a central processing unit( CPU) generates under full load. This power loss depends on the supply voltage and the clock frequency and must be dissipated by heat sinks, heat pipes or Peltier elements. With fast Pentium CPUs, the TDP values are well over 100 W.
The level of dissipation thus reaches areas where thermal dissipation can only be increased to a limited extent. As a result, increasing the clock frequency to increase the CPU performance is also only possible to a limited extent. This is one of the reasons for the development of other CPU architectures such as dual-core processors or quad-core processors.
Thermal design power has led to the development of low-consumption central processing units, the low- and ultra-low-voltage processors. The ULV processors, Ultra Low Voltage (ULV), and the CULV processors, Consumer Ultra Low Voltage (CULV), developed for the consumer sector, have much lower supply voltages of 1.05 V to 1.15 V and operate at lower clock frequencies, resulting in a lower TDP value.
The development of the Thermal Design Power can be shown with the example of the Celeron: The Celeron M has a TDP value of 57 W at a clock rate of 2.2 GHz. At 800 MHz and a reduced data rate of the Front Side Bus( FSB), it has a TDP value of 22 W and in the Celeron M ULV version, it has a TDP value of only 7 W with the same clock rate but a reduced supply voltage of 1.05 V.