Observing Turbo-mode on Linux

# turbostat -v

CPUID GenuineIntel 11 levels family:model:stepping 6:26:4
Nehalem multiplier 22, TSC frequency 2933 MHz
Nehalem 4 cores active: 23 mult, max turbo frequency = 3067 MHz
Nehalem 3 cores active: 23 mult, max turbo frequency = 3067 MHz
Nehalem 2 cores active: 23 mult, max turbo frequency = 3067 MHz
Nehalem 1 core active: 24 mult, max turbo frequency = 3200 MHz
...