benchmark.js

#!/usr/bin/env node
/* eslint-disable no-console */

const regularFunction = () => {
  const a = Math.random()
  const b = Math.random()
  const c = Math.random()

  return a + b + c
}

const closuredFunction = ((a, b, c) => () => {
  a = Math.random()
  b = Math.random()
  c = Math.random()

  return a + b + c
})()

;[10 ** 1, 10 ** 2, 10 ** 4, 10 ** 6, 10 ** 8].forEach(iterations => {
  const regularFunctionStartTime = Date.now()

  for (let i = 0; i < iterations; i++) {
    regularFunction()
  }

  const regularFunctionEndTime = Date.now()
  const closuredFunctionStartTime = Date.now()

  for (let i = 0; i < iterations; i++) {
    closuredFunction()
  }

  const closuredFunctionEndTime = Date.now()

  console.log(
    `Regular function:  Completed ${iterations} iterations in ${regularFunctionEndTime -
      regularFunctionStartTime}ms`
  )
  console.log(
    `Closured function: Completed ${iterations} iterations in ${closuredFunctionEndTime -
      closuredFunctionStartTime}ms`
  )
  console.log('')
})

results.txt

Regular function:  Completed 10 iterations in 0ms
Closured function: Completed 10 iterations in 0ms

Regular function:  Completed 100 iterations in 0ms
Closured function: Completed 100 iterations in 0ms

Regular function:  Completed 10000 iterations in 3ms
Closured function: Completed 10000 iterations in 2ms

Regular function:  Completed 1000000 iterations in 27ms
Closured function: Completed 1000000 iterations in 34ms

Regular function:  Completed 100000000 iterations in 1758ms
Closured function: Completed 100000000 iterations in 3403ms

See the analysis of this code here.