[tonymet]

The animation seems to tax the CPU. I ran Chrome profiler and compared to hackernews (my performance gold standard) ...

Hackernews = 99.9% idle , 0 rendering

Your new blog = 94% idle, 4.7% rendering + painting

Someone mentioned the fans / activity monitor showing cpu usage as well

[kokanee]

I'm not going to dive in and play with it, but often it can help to add the CSS rule "transform: translateZ(0)" in order to force rendering to the GPU instead of CPU.