Intel E7-8891 v2 CM8063601377422 Manuale Utente
Codici prodotto
CM8063601377422
Intel
®
Xeon
®
Processor E7-2800/4800/8800 v2 Product Family
65
Datasheet Volume Two: Functional Description, February 2014
PCU Functional Description
10
PCU Functional Description
This chapter describes the PCU module features along with PECI interfaces in more
detail.
detail.
10.1
Introduction
Power and thermal management functions require the collection of inputs from a wide
variety of sources on the platform. These sources could be dedicated sensors in the
processor or a collection of microarchitectural events. The inputs from these sources
can be used to calculate macro parameters such as temperature, power and energy
consumption.
variety of sources on the platform. These sources could be dedicated sensors in the
processor or a collection of microarchitectural events. The inputs from these sources
can be used to calculate macro parameters such as temperature, power and energy
consumption.
The operating system also provides performance requirements in the form of P-state
requests and idle information in the form of C-state requests. This information can be
used to optimize the current operating point to consume the minimum amount of
power required.
requests and idle information in the form of C-state requests. This information can be
used to optimize the current operating point to consume the minimum amount of
power required.
The platform also provides inputs which are generally invisible to the OS. The
PROCHOT_N signal is one such example, it indicates an overheating condition in one of
the platform agents. Similarly platform agents like Board Management Controller
(BMC) and Intel
PROCHOT_N signal is one such example, it indicates an overheating condition in one of
the platform agents. Similarly platform agents like Board Management Controller
(BMC) and Intel
®
Management Engine (Intel
®
ME) can monitor and set limits through
PECI or DMI2 interfaces. The large variety of agents, sensors and the complex
calculations required to compute optimal parameters has made power management a
very complex function. The complexity has reached a point, where it justifies its own
dedicated processing agent.
calculations required to compute optimal parameters has made power management a
very complex function. The complexity has reached a point, where it justifies its own
dedicated processing agent.
The PCU consists of a dedicated microcontroller; RAM for firmware (PCU microcode),
HW state machines, I/O registers for interfacing to the microcontroller and interfaces to
the hardware units in the processor.
HW state machines, I/O registers for interfacing to the microcontroller and interfaces to
the hardware units in the processor.
below shows the high level
organization of power and thermal management architecture. There are two masters to
the power management architecture, the operating system and HW agents in the
platform. HW agents can be Intel ME in the PCH, BMC, Hardware Monitor in workstation
segment. HW agents may override the OS requests when in conflict. For example; if
the OS requests a P-state which exceeds the power limit set by the Intel ME, IT will be
ignored.
the power management architecture, the operating system and HW agents in the
platform. HW agents can be Intel ME in the PCH, BMC, Hardware Monitor in workstation
segment. HW agents may override the OS requests when in conflict. For example; if
the OS requests a P-state which exceeds the power limit set by the Intel ME, IT will be
ignored.