Improving Performance in FCP X

Posted on by Larry

I’ve been getting emails recently about speed issues with Final Cut Pro X. So, I did some digging to learn how to improve the performance of your system, and, along the way, discover some common trouble-shooting tips.


FCP X takes full advantage of the Mac in terms of processor speed, drive speed, RAM and graphics cards. Decoding common camera codecs like AVCHD, XDCAM HD and others can be extremely difficult mathematically. This is no problem for an up-to-date system, but many people are trying to work with HD codecs on older laptops with slower graphics cards and minimal RAM.

These systems are fully supported as a minimum system requirement and, if you were doing minimum things (editing with DV or ProRes Proxy, for instance), then you will generally be fine. But if you are trying to work with professional formats under pressure, you need a system that is configured properly for that level of work.

The best tip for anyone who is experiencing slow response is add more RAM. I recommend a minimum of 8 GB, if your system supports it. And, if you own a MacPro, buy a faster graphics card with more VRAM. You will notice an immediate difference in speed, no matter what video format they are working on.

Another issue that slows performance, aside from the codec, is the image size. Larger images are harder to work with than smaller images.


Rebuilding Final Cut Pro X preferences can fix certain types of behavioral issues, but will not increase speed or performance. If a system begins to suddenly respond unreliably, then deleting corrupted prefs is a good place to start the troubleshooting. But, before trashing preferences, the first question to ask is always “How much RAM do you have and what is your codec/frame size?” before diagnosing unexpected behavior.

When the system allows you to optimize the original codec, which means to transcode it from whatever format the camera shot into ProRes 422, then optimizing is always a good idea. If the optimization choice is grayed out on the import menu, then FCP X has determined that there will be no benefit to optimizing. If you are working with a large frame size on a minimum system, you may actually be better off working with proxies and waiting until you get to a faster system before finishing at original resolution.


There are two FCP X preference files you need to trash. However, the way you trash them varies between OS X 10.6 and OS X 10.7.

In both cases, start by quitting Final Cut Pro X. Never trash preferences with FCP X running.

OS X 10.6 – Snow Leopard

1. Type Command+H to open your Home directory.

2. Go to the Library > Preferences folder.

3. Trash

4. Trash

5. Empty the Trash.

6. Restart Final Cut Pro X.

Be careful to NOT trash your FCP 7 preferences, if they exist. Pay close attention to the actual spelling of these file names.

OS X 10.7 – Lion

The process is the same, except that Apple hid the Library folder. There are two ways to reveal it:

WAY 1:

Hold down on the Option key and click on the Go menu in the Finder. The Library folder shows up as a selection.


Type Shift+Command+G, or select Go > Go To Folder in the Finder. Then, type ~/Library/ and click Go.


3. Go to the Library > Preferences folder.

4. Trash

5. Trash

6. Empty the Trash.

7. Restart Final Cut Pro X.

Let me know what performance or trouble-shooting tricks you’ve discovered and I’ll add them to this list.

Don’t forget that Apple has extensive Final Cut Pro X support pages here:


8 Responses to Improving Performance in FCP X

  1. Hello Larry,

    Just a quick one — Do you you mean optimise to ProRes 422 rather than ProRes 444?

    • Larry says:

      Sorry, this was a typo, which I just corrected. By definition, optimizing media in FCP X means converting (transcoding) it from its source format into ProRes 422.

      ProRes 4444 is used to move files between applications when you need to retain transparency information in the clip.


  2. One thing I have found that helps (being on a Late 2008 Macbook Pro) is using a utility like iCleanMemory before I do something big like an export, rendering a section, etc. That seems to help prepare the system for heavy processing.

    As always, thanks Larry!

    Matthew Reynolds

  3. Matt says:

    Since trashing the preferences has always been integral to FCP troubleshooting, why hasn’t Apple given us a simple way to do it? I know there are plenty of third party preference management apps, but it seems like a no brainer for Apple to add it as well.

  4. Markus says:

    Thanks for the “delete preferences” info. My FCPX system slowed down to a crawl the other day, but I was on a brand new 17″ MacBook Pro with 8 gigs of RAM. Maybe I was pushing it by working exclusively with sychronized clips in a project.

    As much as I like many of the basic ideas of X, the app continues to be extremely buggy. I worked on a short (but complex) promotional video over the weekend in X (as an experiment) and I must have fired off at least 6 bug reports to Apple. From “X plays phantom audio in the timeline where there is no audio ” to “titles lose their custom font info when a project gets reopened”.

    If I run into that many issues over a weekend, I can only imagine what Apple’s FCPX feedback inbox must look like. I do hope X users are taking advantage of it.

    Thanks again, Larry, for all your help and support!

  5. Seb says:

    I agree with Markus, same kind of experiment for me. the bugs and speed of FCPX is the main Issue to make FCPX unusable for a “Pro” project at this time.

    Let’s hope apple will put some resources to FCPX app in the next 6month otherwise they will loose most of the pros.

    Thanks Larry

  6. Ringo says:

    I have a macbook pro 2.3GHz i7 8GB ram I bought a Promise Pegasus R6 expecting a great performance.
    I’m working on a simple project HD with optimized media Apple ProRes 422, only one layer of video, 5 minutes.
    Working without any software opened, after some time working, the FCPX use all memory, can’t longer play.
    This is terrible!
    This is very sad and very very frustrating.
    I’ll try your tip and see if it works.

    • Larry says:

      I don’t own a Promise RAID, so I can’t be much help here. My best advice, if trashing preferences doesn’t help, is to contact Promise directly.

      Let me know what you find out.


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