Improve Neopixel Peformance?

Thanks Gorden. It's a nice function and really fast. Just tried it with a pixel runner left/right.

//runner (left/right)

var pin = NodeMCU.D1;
pinMode(pin, "output");
var neopixel = require("neopixel");
const leds = 64;

const ledsx3 = 3*leds;
//array with rgb values as Uint8ClampedArray
const base = new Uint8ClampedArray(ledsx3);
var show = new Uint8ClampedArray(ledsx3);
var dot1 = new Uint8ClampedArray(3);
dot1[0] = 128;
dot1[1] = 128;
dot1[2] = 128;
var dot2 = new Uint8ClampedArray(3);
dot2[0] = 128;
dot2[1] = 0;
dot2[2] = 0;
var dot3 = new Uint8ClampedArray(3);
dot3[0] = 0;
dot3[1] = 0;
dot3[2] = 128;

//
//prepare
//
var prepare = function() {
  for (var i=0; i<ledsx3; i++) {
    base[i] = 0;
  }
};

//
//animate
//
var dir1 = 3;
var pos1 = 0;
var dir2 = -6;
var pos2 = leds;
var dly3 = 0;
var pos3 = 3*Math.round(Math.random()*leds);
var start, duration;
var animate = function() {
  start = getTime();
  show.set(base);
  show.set(dot1, pos1);
  show.set(dot2, pos2);
  show.set(dot3, pos3);
  neopixel.write(pin, show);
  pos1 = pos1 + dir1;
  if (pos1 >= ledsx3) dir1 = -3;
  else if (pos1 <= 0) dir1 = 3;
  //duration of all code above: 0.006s
  pos2 = pos2 + dir2;
  if (pos2 >= ledsx3) dir2 = -6;
  else if (pos2 <= 0) dir2 = 6;
  //duration of all code above:  0.007s
  dly3++;
  if (dly3 === 7) {
    dly3 = 0;
    pos3 = 3*Math.round(Math.random()*leds);
  }
  duration = getTime()-start;
  //duration of all code above:  0.008s
};


var onInit = function() {
  setInterval(function() { animate(); }, 10);
};

onInit(); //don't save() this line

Execute at your on risk, epilepsy warning.