Time to address this issue if we want to keep our lovely Neo pixels. Who does not love our Neos. (don't raise your hand).
"The single-wire control protocol used by NeoPixels requires a very steady data stream at 800 kilobits per second. There’s a tiny margin for error, but not very much. Bits must be issued at a precisely controlled rate…the Adafruit_NeoPixel library handles all this behind the scenes, carefully counting the time of each machine code instruction. For every pixel, there’s 24 of these:"
"Meanwhile, the Arduino is normally using small fractions of time here and there... (More)