Editing long (50+min) projects

Hi everybody,
Long time fcp user here, mostly editing episodal drama. FCP is super fast, that's why I choose it above Mediacomposer, and sometimes I can actually talk producers into using the tool. The only problem is working on 50+min projects. Manipulating the storyline starts to lag really quickly.
Does anybody have an idea why this is happening? Too many keywords, media and library on the same (fast) drive... any suggestion would help.
I'm using pores LT rushes by the way. And editing portable on Samsung T5's. MacBook Pro M1 MAX
Do yiHi everybody, long time Final Cut Pro user here, editing episodal drama. Needless to say FCPX on a M1 max is super fast, but one thing doesn't seem to have improved speed-wise: working with long timelines. My episodes are 50+ minutes long and working on them makes the application lag. Now I'm looking for tips and tricks on how to deal with this.Putting your media and your library on different drives, instead of one (fast) drive for example? Doing somthing with the UI? I don't know. Anything that can help.Thanks!

One tip that I received from another forum is putting your cache files on your internal drive. And while it's a little early to know for sure, it does seem to help.

An easy first step is resetting FCP preferences (item 11 on this page):  support.apple.com/en-us/HT203477

In general performance should not degrade dramatically just from a 50 min timeline. Your slowdown might be caused by effects, or having a large # of projects or FCP not using render cache efficiently. An I/O limit would not be my first suspicion -- 4k/23.98 ProRes LT is only about 40 megabytes/sec. That said, if you are editing 3 or 4 multicam angles the I/O load can build up. 

I've had about twenty T5s and they were only about 480 MB/sec best case, and would experience thermal slowdown to about 220 MB/sec under heavy writing. There may be some variation depending on what SSD each manufacturing batch uses, but all of mine were like that.

USB-C SSDs can be very sensitive to cable type. I've had T5 SSDs slow down to 50 megabytes/sec because if using a non-OEM cable. Use only the short, thick cables that came with the drives and do not use any USB hubs.

Edit operations consist of two different I/O streams: large sequential reads from the media files or render cache and small random I/Os to the various SQL databases that make up the project. Normally a fast SSD has no problem handling this but as stated above the T5 might be slower than you think.

I have about 15-20 of the 2TB SanDisk Extreme Portable Gen 2, and they have more consistent performance of about 900 MB/sec under heavy load:  www.amazon.com/dp/B08HN37XC1/

I have about 10 of these 2TB Helix SSDs, and they also remain consistent at about 900 MB/sec under heavy load:  www.amazon.com/dp/B07YCQCDDJ/

If you have many projects, each one is comprised of a separate SQL database inside the library. FCP can definitely slow down when opening the event containing those, but it normally would not cause an individual timeline to slow down.

Make sure  you have plenty of extra space (at least 25% free) on all drives, esp. the system drive. All drives should be formatted APFS or Mac OS Extended Journaled (aka HFS+), not ExFAT, NTFS or anything else.

As a test if you are using an external monitor or wireless audio, temporarily disconnect those and just use the laptop. Sometimes external audio or wireless audio can cause slowdowns. That is just for troubleshooting.

There were some memory leak problems on early versions of Monterey that could cause slowdowns. You can check for this using Activity Monitor's memory tab. The memory pressure graph should remain green, not yellow or red. 

You can check for an effects-related slowdown by duplicating the project, selecting all clips on the timeline with CTRL+A, then deleting all Fx with Edit>Remove Effects. Then try editing operations on the 50 min. timeline minus any Fx and see if it's still slow. If yes, repeat the above but remove half the Fx, then the other half, then 1/4, etc, to narrow down which Fx are causing it. If it's still slow with no Fx, then state that and we can pursue further.

If you have compute-intensive Fx like Neat Video and if background rendering is enabled, FCP will constantly be trying to render those to cache. As a troubleshooting step turn off background rendering via FCP by unchecking Preferences>Playback>Background Render. Then delete all render cache via File>Delete Generated Library Files>Delete Render Files>All.

Did you find any answer?

Same thing here, happens since the begining of fcpx as far as i remember, longform is problematic.

Last projects, HD, all proxies off of thunderbolt SSD, end of timeline moving edits by mouse is fine. The more i try this to the start of timeline the more its slow...

I usualy break edit up into several projects and assemble at the end. The problem is trying to work on new versions in whole timeline Only thing that actually works is forgeting the mouse for edit operations and to use keyboard, nudging is slower than using + / - frames.

Strange thing is skimming and effects, jumping to edits etc is as fast as usual. 

Seems like fcpx is sadly not exactly made for longform

I edit multicam 3streams and 1 audio over 5 hours long not a problem

I've definitely found that too many keywords slows things down. In fact I had a documentary project (2 hours) that I had to split into various different libraries as it just wasn't responsive enough. In the end - I've ported it all over to DaVinci Resolve to do the finishing, which seems to have no issues at all with long form projects.

op, have you used any other software for editing?
I use DaVinci and it works perfectly

OP, did you ever find any fixes? I recently divided a 4-hour-long timeline into 8 different projects. 30 minutes each and I'm STILL having major lag issues.

Shadowfax wrote:

OP, did you ever find any fixes? I recently divided a 4-hour-long timeline into 8 different projects. 30 minutes each and I'm STILL having major lag issues.

Can you give some details on the following:

- Machine year, model and config
- Version of MacOS and FCP
- Details on the 30 minute project. What 3rd-party plugins, any use of optical flow, stabilization, etc, how many compound clips, etc.