Final Cut Pro: The Importance of Scratch Disks
Scratch disks are hard drives (or portions of space on a hard drive) that are used by Final Cut Pro for the temporary storage of files when editing videos. Although Final Cut Pro does not use the space for permanent storage of video files, scratch disks are vital when working with videos or clips that contain a lot of complex effects or transitions.
How Final Cut Pro Uses Scratch Disks
In Final Cut Pro, scratch disks are used to store cache files, imported video and rendering files that are created during editing. If you do not configure your scratch disk properly, Final Cut Pro will not function properly or you may not be able to use the program at all. Therefore, you should always check your scratch disk configuration whenever you start Final Cut Pro, especially if you use portable hard disk drives for scratch disks.
If you use your portable hard drives on several computers, and frequently connect and disconnect to the computer that has Final Cut Pro installed, you need to always make sure that the scratch disk is listed in your Final Cut Pro configuration and make sure that it is set up correctly.
Why Scratch Disks Are Important
Whenever you use your computer, your operating system frequently writes and retrieves information from a swap file on your main hard disk. The swap file is a temporary file that is created to help speed processing and applications and as a virtual replacement for RAM memory. Because not all data requires the speedy processing available with RAM memory, your computer is able to use a swap file for caching files that are not so processor intensive.
This means that data is constantly being written and retrieved from your computer's main hard drive. Because your computer's primary hard drive is used so much, it is not a good candidate as a scratch disk in Final Cut Pro. Rendering and other techniques used in video editing require a lot of processing power, and processes and other data actions occurring on the main hard drive would prevent efficient and timely rendering in Final Cut Pro. Thus, Final Cut Pro requires that a separate scratch drive be used for rendering and editing.
Setting Up the Scratch Disk in Final Cut Pro
Because scratch disks are so vital to editing projects in Final Cut Pro, you'll need to know how to properly set up one. Fortunately, setting up a scratch disk to work in Final Cut Pro is a very straightforward process. You can set up a scratch disk by completing the following steps:
- Open the Final Cut Pro program.
- Go to system settings on the Final Cut Pro menu.
- Ensure that the 'Scratch Disk' tab is selected.
- Click on the set button on the top line of the capture window, and then browse to the folder you created on your hard drive.
- With the selected folder, use the 'Set' buttons and choose Waveform Cache, Thumbnail Cache and Auto Save Vault.
- Also, make sure that these four selections begin with your drive name instead of your username.
- Finally, make sure that you select a specific project folder on your scratch drive or your editing files will be placed all over the volume and may cause problems with other projects on scratch disk.