Navigator: hardwareConcurrency property
Baseline Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since March 2022.
The navigator.hardwareConcurrency
read-only property
returns the number of logical processors available to run threads on the user's
computer.
Value
A number between 1 and the number of logical processors potentially available to the user agent.
Modern computers have multiple physical processor cores in their CPU (two or four cores is typical), but each physical core is also usually able to run more than one thread at a time using advanced scheduling techniques. So a four-core CPU may offer eight logical processor cores, for example. The number of logical processor cores can be used to measure the number of threads which can effectively be run at once without them having to context switch.
The browser may, however, choose to report a lower number of logical cores in order to
represent more accurately the number of Worker
s that can run at once, so
don't treat this as an absolute measurement of the number of cores in the user's system.
Examples
In this example, one Worker
is created for each logical processor
reported by the browser and a record is created which includes a reference to the new
worker as well as a Boolean value indicating whether or not we're using that worker yet;
these objects are, in turn, stored into an array for later use. This creates a pool of
workers we can use to process requests later.
let workerList = [];
for (let i = 0; i < window.navigator.hardwareConcurrency; i++) {
let newWorker = {
worker: new Worker("cpu-worker.js"),
inUse: false,
};
workerList.push(newWorker);
}
Specifications
Specification |
---|
HTML Standard # dom-navigator-hardwareconcurrency-dev |
Browser compatibility
BCD tables only load in the browser