TM2, or "Thermal Monitoring 2", is a throttling control method used on LGA 775 versions of the Pentium 4, Pentium D and Celeron processors and also on the Pentium M series of processors. TM2 reduces processor temperature by lowering the CPU clock multiplier, and thereby the processor core speed. (In comparison, TM1 insert an idle cycle to CPU for thermal control, without decreasing multipliers).