Please read How to Set Preferences & Memory Usage for Peak Performance before you continue reading this article.
History & Caches
Simply put, keep History States and Cache Levels at their default settings, and get into the habit of working on separate Layers, especially if you’re worried you might need to go back after more than 20 History States if you make a mistake while retouching.
Each History State in the History Panel increases the amount of memory or Scratch Disk space that Photoshop is utilizing. You can save your computer memory and improve performance by limiting or reducing the number of History States in Preferences.
The more Cache Levels you have, the slower Photoshop opens the file, but the more responsive it is while you work. The fewer Cache Levels you have, the faster the image loads, but the slower Photoshop performs when working on the image. The default Cache Levels setting is 4, you can change that depending on the types of files you work on and how much RAM you have on your computer.
Optimizing Cache Levels and Tile Size for documents that are:
- Tall and Thin – better for editing images with smaller pixel dimensions that have many layers.
- Big and Flat – better for editing images with larger pixel dimensions and fewer layers.
- Default – somewhere in between. Recommended!
Performance-Friendly Work Habits
1. Work within file-size limitations
The larger the file you’re working with, the more likely it is that you will encounter performance problems.
File size capability for Photoshop:
- PSD files: 2 GB
- TIFF files: 4 GB (CS6 supports larger files)
- PSB files: 4 Exabytes (4 million Tb)
- PDF files: 10 GB
When saving large files for clients, keep in mind that they might be limited by the memory of the device they will be opening it on. Rule of thumb: your masterfiles, which you will keep on your computer, can be large within file-limitations mentioned above. But whenever you’re submitting files to clients or printing labs, keep them as small as possible without compromising their quality. For example, merge the layers inside the file and adjust file size to the print size.
2. Unclutter Your Photoshop
Don’t install all downloaded and purchased plugins, Actions, fonts and brushes into your Photoshop. Having too many resources installed in Photoshop will greatly decrease its performance. Most top artists use a small selection of brushes and Actions that define their own style, so learn to do more with less.
Limiting installed resources will improve your Photoshop performance. Keep all your downloaded freebies in a designated folder on your hard drive. Install items only when they are needed and remove those that you don’t use regularly.
3. New vs. Duplicate Layers
When possible add new empty layer instead of duplicating existing layers with pixels. Duplicate layers double the size of your working document and may significantly decrease Photoshop performance if you’re already short of RAM.
4. Adjustment Layers Vs. Adjustments
Using Adjustment Layers allows you to tweak their settings later in your retouching process and not rely on the number of History States in your History Panel.
5. Work in 8-bit image mode
Photoshop can perform many operations on 16-bit and 32-bit images. However, these images require more memory, scratch disk space and time to process than 8-bit images. Not all filters will work on 16-bit images and even fewer on 32-bit images.
However, if you have soft gradients in the background of your image, working in 8-bit color depth can cause banding. It is recommended to work in 16-bit color depth to avoid color banding.
Learn more about banding and Bit Depth: Qualities of Digital Images: Bit Depth
6. Close unnecessary files and programs
If it is not necessary for your workflow, having extra files or programs running will only compete for memory and cause your overall system to slow down.