Photoshop Tips to optimize performance

Posted on August 30, 2004 in Uncategorized

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Photoshops limitations: Photoshop CS supports a maximum image dimension of 300,000 x 300,000 pixels, which allows for images with a maximum size of 4 GB for TIFF files, and almost unlimited file sizes for images saved in the new native Large Document Format (.psb). Photoshop CS can access only 2 GB RAM, so large files will need to use considerable scratch disk space. Large Document Format files cannot be read by Photoshop 7.0.x or earlier. To optimize performance in Photoshop, apply the following recommendations.

  1. Set Scratch Disks - For the best performance, you should set the primary scratch disk to a defragmented hard drive that has plenty of unused space and fast read/write speeds.
  2. Working with File Browser - File Browser preferences settings to increase performance include: turning off High Quality Previews; reducing the size of images processed by the File Browser; reducing the custom thumbnail size if you've set a larger size than the default; deselect Render Vector File to prevent Photoshop from creating thumbnails of vector files; or turning off background processing.
  3. 16 Bit Functionality - Photoshop CS significantly increases the number of features that can be performed on 16-bit images. However, if your resources are low, reducing your images to 8-bit can improve performance.
  4. Adjusting the Image Cache - Photoshop uses image caching to redraw high-resolution images on-screen faster. With image caching, Photoshop quickly updates a low-resolution version of an image as you edit it. To enable the Image Cache option, specify the number (1 to 8) of low-resolution versions you want Photoshop to store (cache). The more versions you specify, however, the slower Photoshop will open image files. Photoshop's default Image Cache setting is 4. Setting the Image Cache option to 1 disables image caching; only the active screen image is cached. Setting the Image Cache higher than 4 improves the performance when working on larger images, by redrawing them faster.
  5. Deselecting Export Clipboard
  6. Using the Enable Async I/O plug-in - The Enable Async I/O plug-in installed with Photoshop enables faster disk operations (read and write speed). The Enable Async I/O plug-in is enabled by default. If the plug-in is enabled, an asterisk appears after the Efficiency percentage (for example 100%*) in the lower left of Photoshop's image window. To view the Efficiency percentage, choose Efficiency from the pop-up menu in the lower left of the image window. If the plug-in is disabled, a tilde (~) or a "not" sign (¨) appears as the first character in the Enable Async I/O folder name, or the folder or plug-in may be missing.
  7. Disable Detect Watermark plug-in
  8. Minimize Image file size - layers and channels significantly add to the size of a file, you can minimize file size by merging layers and deleting channels when they are no longer needed. Finally, if you are preparing images for color separation, you can work in RGB mode until you are ready to print, and then change the images to CMYK mode.
  9. Minimizing resolutions - Increasing the resolution of an image does not always improve the quality of the image, but may instead only increase its file size. You want the resolution of images to be the highest value your printer can use. Resolutions higher than that only add information that your printer can't use, but must process, thereby increasing print times.

For continuous-tone images, such as photographs, that you plan to print, begin by using a resolution that is 1.5 to 2 times the screen frequency, measured in lines per inch (lpi), that you'll use to print the image. For line-art images, such as drawings, use the same value as your printer's resolution, measured in dots per inch (dpi). For example, if the resolution of your printer is 600 dpi, and you plan to print the image using the printer's default screen frequency of 85 lpi, save continuous-tone images at a resolution between 127 ppi (85 lpi x 1.5) and 170 ppi (85 lpi x 2), and save line-art images at a resolution of 600 ppi.

Recommended resolutions for continuous-tone images:
Output Recommended resolution
Macintosh monitor 72 ppi
Windows-compatible monitor 96 ppi
300 dpi laser printer 100 ppi
600 dpi laser printer 150 ppi
725 dpi inkjet printer 150 ppi
1200 dpi or higher imagesetter 1.5 x the screen frequency (lpi) value you specified
  1. Turning off maximize compatibility
  2. Minimizing the number of layers
  3. Flattening TIFF files - Photoshop allows layers to be saved in TIFF files. Layered TIFF files are larger than flattened TIFF files and require more resources for processing and printing. If you work with a layered TIFF file, save the original layered file as an Adobe Photoshop (*.psd) file; then, when you are ready to save the file in TIFF format, save a copy without layers.
  4. Dragging and dropping between files - Dragging and dropping layers or files is more efficient than copying and pasting them. Dragging bypasses the clipboard and transfers data directly. Copying and pasting can potentially involve more data transfer and may take more time.
  5. Allocating more memory to Photoshop - In Mac OS X, Photoshop's memory is allocated from RAM that is available after the OS has used the amount of RAM it needs. If you do not need to use memory for other applications, you can assign almost all the available RAM to Photoshop (leave at least 20 MB open for overhead processing). You can use a system monitor that graphs memory such as System Manager to determine the best amount of RAM to assign to Photoshop for your computer.

To allocate more memory to Photoshop in Mac OS X:

  1. Choose Photoshop > Preferences > Memory & Image Cache.
  2. In the Memory Usage section, increase the Maximum Used by Photoshop percentage, and click OK.
  3. Restart Photoshop.

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