In the past couple of years of using Final Cut Pro I’ve had few problems in rendering timelines in Final Cut Pro X, but have seen reports of other people facing this issue.
Yesterday I wanted to compare the speed of an old MacBook Pro with my slightly less old iMac. I set up a timeline with one title generator and timed them both.
Mid-2011 27″ iMac 2.5 GHz Core i7 - 23.5 seconds
Mid-2009 17″ MacBook Pro 2.8 GHz Core Duo – 1 hour 19 minutes 15 seconds
Clearly something was up. Although the iMac has every possible advantage over the MacBook, this kind of difference looks like a bug. The most likely culprit is having a lower powered GPU with not enough memory.
It shows that if you do have access to a faster Mac, it is worth moving a problem project to a higher spec system. The speed difference may be orders of magnitude higher than you expect.
If you don’t have access to a faster computer…
Final Cut Pro W
The W is for ‘Workaround.’ Here’s another workaround to add to an already long list…
Seeing that the rendering got very much slower after the render was 30% done, I guessed that there is a programming problem. I tried an alternative way rendering in Final Cut Pro. If it started to slow down, I quit the application. I then restarted Final Cut and started the render again:
1. I timed the render until 36%, when it started to slow down.
2. I stopped the render (using Command-.) and quit Final Cut
3. I started a new render (which always start at 0%), timed it until it reached 36% again
4. I stopped the render (using Command-.) and quit Final Cut
5. I started a new render, timed it until it reached 50%
6. I stopped the render (using Command-.) and quit Final Cut
7. I timed one more render until it finished.
The render time – not including the quitting and restarting of Final Cut Pro – reduced from 1 hour 19 minutes to 2 minutes 20 seconds.
What about exporting movies?
This workaround may be useful while editing to get out of a big rendering problem, but doesn’t directly help when sharing Quicktime movies. Unlike Final Cut Pro 7, X doesn’t use rendered frames when generating Quicktime movies. Usually this is good news as X is faster when outputting movies than when it renders timelines. In the case of a clip, generator, or plugin causing Final Cut to slow down an unfeasible amount, export becomes a problem.
The workaround in this case is to export your timeline as a series of movies (quitting and restarting Final Cut before each export), reimporting them and joining them together in a new project!
This method took 2 minutes 55 seconds of rendering – not including restarting the app three times or exporting the combined movie, but better than waiting over an hour!
Now to report this bug to Apple…