Final Cut Pro X: why does it take so long to render video?

I’m quite a fan of Final Cut Pro X, or FCPX, as it’s known to its fans. It’s a refreshed version of the much-loved Final Cut Pro, on which a huge amount of professional video work has been done.

The relaunch was very far from smooth, however, and saw Apple commit cardinal sins, such as not having all the functionality required by pro users at launch, and cutting off the availability of licences for the older version – a real case of gun meets foot. But over subsequent months, several revisions put back many of the power-user tools.

I like its power and depth, yet it’s actually quite easy to use once you wrap your head around the user interface and workflow, which isn’t based around the usual concepts of open/work/save/close. Everything in FCPX appears to be available all the time – all your so-called “assets” such as video, audio and the rest, along with all your projects in progress.

There’s no ‘Damn it, I need maximum warp, Scotty’ button

My editing task last week was simple enough: create a picture-in-picture composite from two HD video streams, then output the resulting video. Nothing particularly complicated, and well within the capabilities of a fully stuffed MacBook Pro with 16GB of RAM and 768GB of SSD disk space – or so I thought, until I came to output the files to disk, when the whole system came to a juddering halt.

You don’t just export files in FCPX – you queue them up for an export routine that runs in the background. The upside is that you can continue to work in the foreground while the big disk churns and the number crunching happens in the background. The downside is that there’s a woeful lack of control over the background process – you simply have to let it run until it’s done. There’s no “Damn it, I need maximum warp, Scotty” button, nor any other way of indicating that you’d really quite like it to pause what it’s doing and focus its attention here, please.

Rendering 6GB of video took the thick end of 24 hours, and for much of that time the CPUs were sitting idle, almost as if the software was contemplating some zen inner meaning.

Randomly clicking on the desktop inside the app sometimes made the software wake up and do a little more work, but clearly something’s very wrong. Others have reported the same problem, but working out what’s at fault is proving difficult.