Yeah, I've noticed that Chrome is especially bad since it still does very little to GPU-accelerate SVG. Frankly, one reason I had left it enabled for so long was to make a point about Chrome's bad GPU+SVG support. Why should it be necessary to use the CPU to move a semi-circle?
But in any case, I'd rather not distract from the points I'm trying to make in the blog entry, so the background is now off by default.
Where does it actually run well? It doesn't peg a core on Safari, but scrolling still feels laggy and unpleasant. I initially assumed you'd implemented your own inertial scrolling, as with old Google mobile sites.
It runs well on all my PCs, which admittedly are all Windows. It's just an SVG+SMIL animation. My opinion is that in 2013, it should run entirely on the GPU. But I acknowledge that's not the case as much as I think it should be.
On my box, it uses ~2.1% CPU and ~16% GPU in Aurora.
But in any case, I'd rather not distract from the points I'm trying to make in the blog entry, so the background is now off by default.