os.cpus

History

os.cpus(): Object[]

Returns:Object[]

Returns an array of objects containing information about each logical CPU core. The array will be empty if no CPU information is available, such as if the /proc file system is unavailable.

The properties included on each object include:

Attributes

model:string

speed:number

(in MHz)

times:Object

user:number

The number of milliseconds the CPU has spent in user mode.

nice:number

The number of milliseconds the CPU has spent in nice mode.

sys:number

The number of milliseconds the CPU has spent in sys mode.

idle:number

The number of milliseconds the CPU has spent in idle mode.

irq:number

The number of milliseconds the CPU has spent in irq mode.

[
  {
    model: 'Intel(R) Core(TM) i7 CPU         860  @ 2.80GHz',
    speed: 2926,
    times: {
      user: 252020,
      nice: 0,
      sys: 30340,
      idle: 1070356870,
      irq: 0,
    },
  },
  {
    model: 'Intel(R) Core(TM) i7 CPU         860  @ 2.80GHz',
    speed: 2926,
    times: {
      user: 306960,
      nice: 0,
      sys: 26980,
      idle: 1071569080,
      irq: 0,
    },
  },
  {
    model: 'Intel(R) Core(TM) i7 CPU         860  @ 2.80GHz',
    speed: 2926,
    times: {
      user: 248450,
      nice: 0,
      sys: 21750,
      idle: 1070919370,
      irq: 0,
    },
  },
  {
    model: 'Intel(R) Core(TM) i7 CPU         860  @ 2.80GHz',
    speed: 2926,
    times: {
      user: 256880,
      nice: 0,
      sys: 19430,
      idle: 1070905480,
      irq: 20,
    },
  },
];

JavaScript

nice values are POSIX-only. On Windows, the nice values of all processors are always 0.

os.cpus().length should not be used to calculate the amount of parallelism available to an application. Use os.availableParallelism() for this purpose.