Logging with runtime level selection in node.js

basic.js

var N = process.argv[2] || 1000000;
function log () {
  console.log.apply(console,arguments);
}
for (var i=0; i<N; i++) {
  log("this is message"+i);
}

// didn't run to completion, stopped at ~5m18s
// real    5m18.449s
// user    5m15.645s
// sys     0m5.304s

cond.js

var LOG = false;
var N = process.argv[2] || 1000000;
function log () {
  if (!LOG) return;
  console.log.apply(console,arguments);
}
for (var i=0; i<N; i++) {
  log("this is message"+i);
}

// real    0m0.331s
// user    0m0.294s
// sys     0m0.028s

const.js

var LOG = false;
var N = process.argv[2] || 1000000;
function log () {
  console.log.apply(console,arguments);
}
for (var i=0; i<N; i++) {
  LOG && log("this is message"+i);
}

// real    0m0.117s
// user    0m0.094s
// sys     0m0.016s

func.js

var LOG = false;
var N = process.argv[2] || 1000000;
function log () {
  console.log.apply(console,arguments);
}
if (!LOG) log = function(){};
for (var i=0; i<N; i++) {
  log("this is message"+i);
}

// real    0m0.311s
// user    0m0.272s
// sys     0m0.027s

Ran with time (node file.js >/dev/null 2>&1), took the worst times out of 4 consecutive runs.