Passos de Frequência de Hardware - Intel P-State vs CPUFREQ ACPI

Question

Eu tenho Intel Xeon Phi 7210 executando CentOS 7 com o kernel 3.10.0-514.el7.x86_64 . Estou comparando quais etapas de frequência estão disponíveis quando eu inicializo o sistema em intel p-state vs quando o sistema usa acpi cpufreq . Eu corro sudo cpupower frequency-info para seguir dois logs.

Intel P-State

analyzing CPU 0:
  driver: intel_pstate
  CPUs which run at the same hardware frequency: 0
  CPUs which need to have their frequency coordinated by software: 0
  maximum transition latency:  Cannot determine or is not supported.
  hardware limits: 1000 MHz - 1.50 GHz
  available cpufreq governors: performance powersave
  current policy: frequency should be within 1.40 GHz and 1.40 GHz.
                  The governor "performance" may decide which speed to use
                  within this range.
  current CPU frequency: 1.30 GHz (asserted by call to hardware)
  boost state support:
    Supported: yes
    Active: yes

CPUFREQ da ACPI

analyzing CPU 0:
  driver: acpi-cpufreq
  CPUs which run at the same hardware frequency: 0
  CPUs which need to have their frequency coordinated by software: 0
  maximum transition latency: 10.0 us
  hardware limits: 1000 MHz - 1.30 GHz
  available frequency steps:  1.30 GHz, 1.30 GHz, 1.20 GHz, 1.10 GHz, 1000 MHz
  available cpufreq governors: conservative userspace powersave ondemand performance
  current policy: frequency should be within 1000 MHz and 1.30 GHz.
                  The governor "conservative" may decide which speed to use
                  within this range.
  current CPU frequency: 1000 MHz (asserted by call to hardware)
  boost state support:
    Supported: yes
    Active: yes

Por que dois drivers de escala diferentes mostram limites de frequência de hardware diferentes? Para intel p-state , vejo limites de frequência de 1GHz a 1.5GHz e, por outro lado, acpi cpufreq mostra 1GHz a 1.3GHz .

Como por folha de dados, o processador acima pode ser executado em 1.5GHz com turbo boost, é por isso que ele não está disponível para acpi cpufreq ?

Alguma razão específica para isso?

Obrigado.