Hi, I'm obviously a novice when it comes to final cut pro so I'm here asking for help because I'm really feeling helpless right now. I've been editing a very large file and lately, I've noticed that it has been crashing a lot more frequently than it was before and then I realized I was running out of space. I also noticed that it crashed every time I began to export as a test but I also put this down to running out of space. I took a look at my backups folder in Final Cut after doing some research and I noticed these backup files (Three of them are nearly 200gb files) I think it would do me a lot of favours even deleting one of these 200gb files but tbh I don't know what is even safe to delete and I would hate to ruin any progress I made of the video that I was editing as it is nearly finished My question is what do these files actually contain for example the 200gb backup files compared to the 2gb files. I've made a complete mess here and I don't know what I'm doing so any help and advice is much appreciated. Many Thanks - J
A common cause of space consumption in FCPX is render files, often caused by background rendering. To quickly and safely address this, turn off background rendering in FCPX preferences, under the "Playback" tab. Then delete all render files with Files>Delete Generated Library Files>Delete Render Files>All.
A free and safe tool to evaluate overall Mac space consumption is OmniDiskSweeper. It contains no adware or malware. It builds a column-style list of what folders contain the most space, enabling you to quickly find where disk space is consumed:
The backups in /Movies/Final Cut Backups are normally not that large. They contain no media, proxies or cache, just the edits themselves in "lean" libraries. However -- if you've been using FCPX for a long time and have lots of old projects, the space can slowly add up. But on my machine I've worked on huge productions for years and have never deleted any backups, and the total space is only 59GB.
You do not need the backup files but for safety I would never delete those. They can be safely copied to some external drive for archival storage. Just be sure it is *these* library files in the above-mentioned folder, not some other files. If you ever need one in the future you can just copy it back and double-click on it to load in FCPX.
If you have lots of older libraries from past projects, those also will take up space. They often contain render files, proxy files, etc. which can be safely deleted to safe space. To avoid loading each one in FCPX and doing this manually, the easiest way is get the inexpensive 3rd-party utility Final Cut Library Manager. It is easy to use and very safe. It will not delete anything valuable:
Hi Joema, thank you for your response. Background rendering has been turned off since I installed the program I have had a little bit of experience with Final Cut Pro before and I know well enough to turn that off. In regards to the files in final cut backups, the large files are actually in User > Movies and I believe these are library files? The thing is there are about three files out of around 7 here that are around 200gb in size 3 huge files and I don't know the impact of deleting some of these but I need to in order to carry on working I'm just terrified of deleting one of those huge files and the impact it will have on my current project. Would it be best to buy an external HDD and start putting these libraries on there 1 by one and then deleting them off the iMac and see how that goes? and if something goes wrong I can put it back or load it from the external drive?.
LemonSurprise wrote: ...In regards to the files in final cut backups, the large files are actually in User > Movies and I believe these are library files? The thing is there are about three files out of around 7 here that are around 200gb in size 3 huge files and I don't know the impact of deleting some of these but I need to in order to carry on working I'm just terrified of deleting one of those huge files and the impact it will have on my current project. Would it be best to buy an external HDD and start putting these libraries on there 1 by one and then deleting them off the iMac and see how that goes?...
If the large libraries are in /Movies, not in /Movies/Final Cut Backups, those are regular (not backup) FCPX libraries. You shouldn't delete those without understanding what they contain. If those libraries contain cache files, those can be safely deleted. You'd have to load each library in FCPX then for each one do Files>Delete Generated Library Files>Delete Render Files>All.
If the media for those libraries was imported using "copy to library", not "leave files in place", then that media is likely taking up lots of space. That or the containing library cannot be deleted without carefully understanding what the media is and whether you need it.
In general you can copy those libraries to an external drive, then use them there or later copy them back to the main drive. However if the libraries contain a mixture of "copy to library" media and also "leave files in place" media, the projects in those libraries may depend on both sets of media -- part inside the library and part outside. You can inspect this using the Library Inspector. This Larry Jordan article shows how:
Hi joema, thank you for the in-depth and informative reply. I went ahead and got a 1TB hard drive and copied across literally 500gb of libraries across that I wanted to delete to free up space on my iMac. My only problem now is that the video is still crashing upon export it just says "Preparing to share" and then you get the beach ball icon and it says not responding on the application icon when you right-click. The whole project now is unrendered but I have rendered it several times throughout and I believe this was the cause of those huge files and running out of space. I have about 450gb on the iMac I'm just worried about rending those files again and everything starting to mess up as my iMac fills up again but I believe this may help with the export crashing?. Thank you very much for your help.
LemonSurprise wrote: ... the video is still crashing upon export it just says "Preparing to share" and then you get the beach ball icon and it says not responding on the application icon when you right-click...
Based on you stating you might be hitting an out of space condition, we gave the previous advice. No matter what the actual cause, it was a good idea to ensure you have plenty of drive space. So getting the extra drive and moving the libraries off was not wasted time or money.
However there are other reasons FCPX could hang or crash during export. Most commonly it is a 3rd-party effect or plugin, but there are also other possibilities. We need to know the following:
- Version of FCPX
- Version of MacOS
- Year and model of Mac computer
- What camera codecs are being used. You can get that by playing the source clips in Quicktime Player and doing CMD+I.
If you are running the Chrome browser or any browser based on Chrome such as Brave, this can cause unpredictable hangs or crashes. Chrome mis-uses the MacOS VideoToolBox framework, causing this. Make sure Chrome is not running and not in memory (not just minimized).
If you are not on 10.4.10 and editing HEVC material, this can cause a hang or crash under certain narrow conditions. The solution to that is update to 10.4.10.
3rd-party plugins run within the address space of FCPX. A bug in any plugin can cause FCPX to hang or crash. One way to rule this in/out is make a snapshot duplicate of your project, open that, select all clips with CMD+A, then do Edit>Remove Effects. Then export that timeline without effects. If that fails, tell us.
If that works, that implies it is some effect. First evaluate what effects and plugins you have installed and update any you can, esp. from CoreMelt. CoreMelt plugins can be updated from this page:
After doing that, open the original timeline, select all clips with CMD+A, then render timeline with CTRL+R. Do not touch machine while that's running, else the render will halt. Make sure it finishes and no render dots are showing above the timeline. If the render fails or hangs, state that. If it completes, then try to export using this preset: File>Share>Master File>Settings, Format: Computer, Video Codec: H.264 Faster Encode, Resolution: 1280 x 720. If that works or fails, let us know.
Normally if the render completes the export will work OK. This is because all the hard work is done during the render, and export is then fairly easy.
if it still hangs or crashes during either render or export phases, make another snapshot duplicate of the timeline, open it, leave Fx in place, but delete 1/2 of the timeline and try to export that (using above preset). If that works, repeat the above but do the other 1/2. If both fail, repeat the above but delete 3/4 of the timeline and only export 1/4, then repeat on each 1/4. This procedure attempts to narrow down what region and what effect or plugin might be causing the problem.
Throughout all this keep an eye on your disk space. On any drive you need to maintain about 20% free space.
If the entire machine ever hangs or crashes (not just FCPX) that indicates a system-layer or hardware problem, not one with FCPX. If that happens let us know and we can give advice.