Platform Environment Control Interface (PECI) is an

Intel Intel Corporation is an American multinational corporation and technology company headquartered in Santa Clara, California, and Delaware General Corporation Law, incorporated in Delaware. Intel designs, manufactures, and sells computer compo ...

proprietary single wire

serial interface A serial port is a serial communication interface through which information transfers in or out sequentially one bit at a time. This is in contrast to a parallel port, which communicates multiple bits simultaneously in parallel. Throughout mo ...

that provides a communication channel between

Intel processors This generational list of Intel processors attempts to present all of Intel Corporation, Intel's microprocessor, processors from the 4-bit computing, 4-bit Intel 4004, 4004 (1971) to the present high-end offerings. Concise technical data is give ...

and

chipset In a computer system, a chipset is a set of electronic components on one or more integrated circuits that manages the data flow between the processor, memory and peripherals. The chipset is usually found on the motherboard of computers. Chips ...

components to external system management logic and thermal monitoring devices. Also, PECI provides an interface for external devices to read processor temperature, perform processor manageability functions, and manage processor interface tuning and diagnostics. Typically in server platforms,

CPU A central processing unit (CPU), also called a central processor, main processor, or just processor, is the primary processor in a given computer. Its electronic circuitry executes instructions of a computer program, such as arithmetic, log ...

s are the PECI slaves and

Platform Controller Hub The Platform Controller Hub (PCH) is a family of Intel's single-chip chipsets, first introduced in 2009. It is the successor to the Intel Hub Architecture, which used two chipsa northbridge and southbridge, and first appeared in the Intel 5 Se ...

(PCH) is the PECI master, meanwhile in client segment, CPU is usually the PECI slave and EC/ BMC is the PECI master. PECI was introduced in 2006 with the

Core 2 Duo Intel Core is a line of multi-core (with the exception of Core Solo and Core 2 Solo) central processing units (CPUs) for midrange, embedded, workstation, high-end and enthusiast computer markets marketed by Intel Corporation. These processors ...

microprocessor A microprocessor is a computer processor (computing), processor for which the data processing logic and control is included on a single integrated circuit (IC), or a small number of ICs. The microprocessor contains the arithmetic, logic, a ...

s. Support for PECI was added to the

Linux kernel The Linux kernel is a Free and open-source software, free and open source Unix-like kernel (operating system), kernel that is used in many computer systems worldwide. The kernel was created by Linus Torvalds in 1991 and was soon adopted as the k ...

version 5.18 in 2022.

Thermal monitoring details

While previous thermal management technologies have made use of thermal diodes, PECI instead uses on-die digital thermal sensors (DTS). These sensors, after being calibrated at the factory, are able to provide digital data concerning processor

temperature Temperature is a physical quantity that quantitatively expresses the attribute of hotness or coldness. Temperature is measurement, measured with a thermometer. It reflects the average kinetic energy of the vibrating and colliding atoms making ...

information. The PECI

bus A bus (contracted from omnibus, with variants multibus, motorbus, autobus, etc.) is a motor vehicle that carries significantly more passengers than an average car or van, but fewer than the average rail transport. It is most commonly used ...

, allowing access to this data from

components, is a

proprietary {{Short pages monitor