It wasn't mentioned in the article, but, it is very important to note: CAGradientLayer is not GPU-backed.
In other words, the comparison is between the CPU redrawing a gradient 60x a second, and, an image being moved around on screen. Not entirely surprising that the one that does less rendering is going to be faster.
In other words, the comparison is between the CPU redrawing a gradient 60x a second, and, an image being moved around on screen. Not entirely surprising that the one that does less rendering is going to be faster.