> Comparatively slow to some desktop PCs perhaps but it's still an i3-3217U, HD Graphics 4000.
Slow core coupled with the worst graphics vendor in the industry.
When you have to fallback to software, it takes quite a bit of computing power. That's why something like an ION or a PI is a problem. If you have to depend on the included CPU, you're toast.
It takes a LOT of of computational power to make up for the lack of good specialty silicon.
Modern codecs, High definition. High bit rates.