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The UltraSPARC T2 Processor with CoolThreads Technology

Sun Microsystems, Inc.

Power Management

Beyond the inherent efficiencies of CMT design, the UltraSPARC T2 is the first processor to incorporate unique power management features at both the core and memory levels of the processor. These features include reduced instruction rates, parking of idle threads and cores, and ability to turn off clocks in both cores and memory to reduce power consumption. Substantial innovation is present in the areas of:

Limiting speculation such as conditional branches not taken

Extensive clock gating in the data path, control blocks, and arrays

Power throttling that allows extra stall cycles to be injected into the decode stage

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Sun Microsystems T5120, T5220 manual Power Management