Caution: Unexplained Timeline Slowdowns in Final Cut Pro

Tangier Clarke brought this issue to my attention.

If you have a complex Apple Final Cut Pro timeline, especially if it was imported using XML, it may slow almost to unresponsiveness.

Tangier used XML and SendToX from Intelligent Assistance to transfer a Premiere Pro project into Final Cut Pro. SendToX adds red to-do markers to items to draw your attention to what has changed or been substituted on the FCP timeline.

Once that XML file was imported, Final Cut performance drastically slowed down. Tangier detailed the issues this way:

• The project originated in Premiere Pro. SendToX by Intelligent Assistance was used to migrate it to Final Cut Pro.
• I initiated the conversation on FCP.co in order to figure out why Final Cut performance was so degraded.
• Using Apple’s Xcode and and Instruments to examine the timeline, user Joema helped me discover what contributed to Final Cut’s choppy UI performance. Specifically this was a complex more-than-90-minute timeline with too many markers, compound clips, and storylines. This complexity caused FCP to slow significantly.
• The results were the same if media was online or not. It also made no difference when running on Intel or Apple Silicon systems. Even FCP’s SQLlite database performance was tested.
• Other users jumped in to test and examine FCP’s sluggish performance on multiple Apple computers through a process of progressive timeline elements elimination and FCP asset locations.
• SendToX is not the issue and although performance is improved on Apple Silicon, it’s still not ideal and there seems to be an undetermined threshold for FCP’s UI performance and the complexity of a timeline.

Here’s the thread on FCP.co that explains this in more detail.

Link: Too Many To-Do Markers Cause Timeline Slowdowns

Tangier also emphasized:

“Gregory Clarke at Intelligent Assistance is always helpful to me and very responsive; so much so that he’s updated apps after I’ve discovered an issue or requested a feature that would significantly help the FCP community.

Although SendToX is incredibly thorough in bringing as much information over as it can and translating one NLE’s timeline for another, I hope people don’t read this and think SendToX is the problem. Its results can give FCP a lot to chew on, but from user Joema’s findings, those results shouldn’t impede FCPs heralded responsiveness. There’s something else going on still to be discovered. Joema is reporting all of this to Apple.”

I contacted Greg Clarke, at Intelligent Assistance, about this. He, too, thinks this is more than a marker problem. He wrote:

SUMMARY

Adding a few dozen To-Do markers to any Final Cut project won’t cause any problems. However, if you regularly import transcripts into FCP, or use XML to transfer projects, take the time to read this thread, especially if your system seems to be slower than usual.

We don’t yet have a solution, but we do have a better understanding of the problem. I’ve also sent a note to Intelligent Assistance to see if we can learn more.