Some people say it does, some swear it doesn't matter, but now we have a definitive answer. Also we post the one click tweak that can really speed up FCPX.

I've seen people write that it doesn't matter if an FCPX timeline is rendered or not, the export time for a project will be the same.  I've never felt that was correct, so I thought I'd set up a test to see if rendering helps or has no impact on export speeds.

I used the same timeline for each test, rebooting FCPX and also clearing out all render files each time to make sure nothing was 'reused' in a subsequent export.  The timeline was 1080p with lots of effects applied that I thought would really tax the machine to highlight a differential.

I got some interesting results:

Pretty conclusive eh? 

Let me stress the importance of changing the default render mode again. Out of the box (or freshly downloaded or prefs reset) the preference will be set to trigger off the background render after 0.3 seconds of inactivity.

I think this is far too short a 'pause' and have mine set anywhere between 7 to 10 seconds. This avoids the machine switching inbetween modes all the time and getting rid of that annoying task of having to wake the machine up out of rendering.

background rendering fcpx

Yes, background rendering does help, but by setting it to 10 seconds, not only is it out of the way, but it will also kick in and render if you get distracted by a phone call, making a cup of tea or even the producer chipping in comments on your work!

I really think this short timed default mode is a mistake and Apple should put it to something more sensible.

But back to the bottom line, yes, rendering makes a hell of a difference!