Intel i7-960 AT80601002727AA User Manual

Datasheet 

87

The processor features Enhanced Intel SpeedStep Technology. Following are the key 

features of Enhanced Intel SpeedStep Technology:

• Multiple voltage and frequency operating points provide optimal performance at the 

lowest power. 

• Voltage and frequency selection is software controlled by writing to processor 

MSRs:

— If the target frequency is higher than the current frequency, V

CC

 is ramped up 

in steps by placing new values on the VID pins and the PLL then locks to the 

new frequency.

— If the target frequency is lower than the current frequency, the PLL locks to the 

new frequency and the V

CC

 is changed through the VID pin mechanism.

— Software transitions are accepted at any time. If a previous transition is in 

progress, the new transition is deferred until the previous transition completes.

• The processor controls voltage ramp rates internally to ensure smooth transitions.
• Low transition latency and large number of transitions possible per second:

— Processor core (including shared cache) is unavailable for less than 5 µs during 

the frequency transition.