[mappu]

"VP9 encoding (using libvpx) is horrendously slow – like, 50x slower than VP8/x264 encoding. This means that encoding a 3-minute 1080p clip takes several days on a high-end machine. ... libvpx multithreading [encoding] performance is deplorable. It gains virtually nothing."[1]

1. https://blogs.gnome.org/rbultje/2014/02/22/the-worlds-fastes... n.b. x264 comparisons were taken with `--preset veryslow` which understates x264's potential performance by an order of magnitude. From the same link: "it can be fast, and it can beat x264, but it can’t do both at the same time."

[TD-Linux]

This is old. libvpx 1.4.0 is a lot faster now and has multithreading. On my i7-4900MQ laptop, I get about 3fps encoding 1080p content. Still very slow, but 24 minutes for a 3 minute clip, not days.