OS X slower than Linux, slower than native for short strings

I was benchmarking this library on my laptop and it is more than 2 times slower than native implementation. Is the testing code wrong or the benchmark in readme is wrong.

HW MacBook Pro (15-inch, 2016) 2,7 GHz Intel Core i7 16 GB 2133 MHz LPDDR3

Code

var now = require('performance-now')
var b64 = require('64')

function run (fn, desc) {
  var start = now()
  for (var i = 0; i < 1000000; i++) {
    fn()
  }
  var end = now()
  console.log(desc, (end - start).toFixed(2), 'ms')
}

console.log('NODE', process.version)
run(() => b64.decode(Buffer.from(b64.encode(Buffer.from('test string')), 'base64')), '64')
run(() => Buffer.from(Buffer.from('test string').toString('base64'), 'base64').toString('ascii'), 'native')

Results

NODE v8.1.4
64     2304.52 ms
native 1058.34 ms

NODE v7.6.0
64     2644.51 ms
native 1180.36 ms

NODE v6.10.2
64     2964.18 ms
native 1373.59 ms

[lovell]

I’ve updated the upstream base64 library to the latest commit and performance is much improved - see https://github.com/lovell/64#performance

OS X (clang) still doesn’t seem to produce quite as efficient code as Linux/Windows but in summary processing Buffers longer than ~300 bytes will benefit from this module.

There is also a threshold for the decision to use this shared library vs Buffer’s own implementation - see https://github.com/lovell/64/blob/master/index.js#L7-L8 - thanks for this idea.

This is available via npm as v0.1.2.

Thanks for reporting this and your help debugging.

[lovell]

Thanks for confirming that --build-from-source makes no difference. The OS X discrepancy may be a problem with clang and/or the base64 library code itself.

I quite like the idea of implicitly switching implementations based on input size, plus this is where your suggestion of a graph showing input size against performance would help.

In terms of the API accepting strings, we’d need to ensure that the type-detection overhead doesn’t slow things down too much. Happy to accept a PR for this if you’re willing and able 😃