Specify scratch disks to improve system performance

When you edit a project, Premiere Pro uses disk space to store files required by your project, such as captured video and audio, conformed audio, and preview files that you create manually or that are created automatically when exporting to certain formats. Premiere Pro uses conformed audio files and preview files to optimize performance, allowing real-time editing, 32-bit floating-point quality, and efficient output.

All scratch disk preferences are saved with each project. You may select different scratch disk locations for different projects. If you reopen an earlier project after editing another project with different scratch disk locations, Premiere Pro will seek out the files belonging to the earlier project at the scratch disk locations you chose for that project.

If you delete preview files or conformed audio files for a project, Premiere Pro automatically recreates them when you reopen the project.

By default, scratch disk files are stored where you save the project. The scratch disk space required increases as sequences become longer or more complex. For best performance, it is recommended that you dedicate a hard disk or disks, (other than the disk where you keep your project file, your operating system files, or your files for applications) strictly to your media assets. That way your media disks can access and play media files as fast as possible, without having to access other files. If your system has multiple disks, you can use the Project > Project Settings > Scratch Disks command to specify which disks Premiere Pro uses for media files. This is best done when you set up a new project.

In terms of performance, it’s usually best to dedicate a different disk to each asset type, but you can also specify folders on the same disk. You can specify unique scratch disk locations for each of the following types of files:
Captured Video
Video files that you create using File > Capture.
If you transfer video files to a scratch disk folder before creating the project for them, specify the folder containing the video files for Captured Video.

Captured Audio
Audio files that you create using File > Capture, or by recording through the Audio Mixer as when recording a voiceover.

Video Previews
Files created when you use the Sequence > Render Entire Work Area command, export to a movie file, or export to a device. If the previewed area includes effects, the effects are rendered at full quality in the preview file.

Audio Previews
Files created when you use the Sequence > Render Entire Work Area command, use the Clip > Audio Options > Render And Replace command, export to a movie file, or export to a DV device. If the previewed area includes effects, they are rendered at full quality in the preview file.

Specify scratch disks

You set up scratch disks in the Scratch Disk pane of the Preferences dialog box. Before changing scratch disk settings, you can verify the amount of free disk space on the selected volume by looking in the box to the right of the path. If the path is too long to read, position the pointer over the path name, and the full path appears in a tool tip.

  1. Choose Project > Project Settings > Scratch Disks.
  2. Identify a location for each type of file named in the dialog box. Premiere Pro creates a subfolder named for each file type (for instance, Captured Video) and stores the folder’s associated files in it. The menu lists three default locations:
    My Documents (Windows) or Documents (Mac OS)
    Stores scratch files in the My Documents folder (Windows) or Documents folder (Mac OS).

    Same As Project
    Stores scratch files in the same folder where the project file is stored.

    Custom
    Allows you to specify a location of your choosing. Choose Custom, then click Browse and browse to any available folder.

Optimizing scratch disk performance

For optimum performance, follow these guidelines:

  • If your computer has only one hard disk, consider leaving all scratch disk options at their default settings.

  • Set up scratch disks on one or more separate hard disks. In Premiere Pro, it’s possible to set up each type of scratch disk to its own disk (for example, one disk for captured video and another for captured audio).

  • On Windows, specify only partitions formatted for the NTFS file format as scratch disks. On Mac OS, use partitions formatted for Mac OS Extended. FAT32 partitions are not recommended for video. They do not support large file sizes.

  • On Mac OS, disable journaling for best performance.

  • Specify your fastest hard disks for capturing footage and storing scratch files. You can use a slower disk for audio preview files and the project file.

  • Specify only disks attached to your computer. A hard disk located on a network is usually too slow. Avoid using removable media because Premiere Pro always requires access to scratch disk files. Scratch disk files are preserved for each project, even when you close the project. They are reused when you reopen the project associated with them. If scratch disk files are stored on removable media and the media are removed from the drive, the scratch disk won’t be available to Premiere Pro.

  • Although you can divide a single disk into partitions and set up partitions as scratch disks, this doesn’t improve performance because the single drive mechanism becomes a bottleneck. For best results, set up scratch disk volumes that are physically separate drives.

  • You can capture audio and video to separate drives, if this is supported by the format codec. (This is not supported by the native DV and HDV capture in Premiere Pro.) Set the locations for new files by choosing Edit > Preferences > Scratch Disks (Windows) or Premiere Pro > Preferences > Scratch Disks (Mac OS). If you don’t change the defaults, all files captured or created by Premiere Pro are stored in the same folder in which it stores the project files.