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Optimize performance | Photoshop CS4, CS5, CS6
Key steps to optimize Photoshop CS5 performance
Knowing which hardware works best for your work environment is just part of the performance story. To ensure that your carefully selected hardware works to its full potential, optimize Photoshop and fine-tune your operating system. And if you’re unable to change hardware, use the following guidelines to adjust Photoshop and your operating system preferences to realize performance gains without added expense.
1. Allocate your scratch disk correctly
To set your scratch disk, choose Edit > Preferences > Performance (Windows) or Photoshop > Preferences > Performance (Mac). Then, in the Scratch Disk section of the panel, select the drive that has the most free space—preferably not your system or startup drive. If you have other drives listed, you can also allocate these as extra scratch drives. Photoshop will use the drive listed first until it is full and then move to the next drive if even more memory is needed. You can change the order in which the drives will be used by selecting a drive and then using the Up or Down Arrow keys to change its position in the list. Place your system or startup drive in last position. The performance of systems whose Efficiency result (see boxout below for details) regularly falls below 95% when conducting simple operations will be improved by the correct allocation of fast scratch disks or the addition of extra RAM.
2. Separate the Photoshop scratch disk from operating system virtual memory
As most operating systems employ a virtual memory system similar to the one in Photoshop, it is recommended that scratch disks be positioned on a different drive than the one your computer uses for its virtual memory system. In general, the operating system’s virtual memory, or swap file, is stored on the startup or system drive. To help with overall Photoshop and Windows/Mac performance, ensure that you don’t position the scratch disk on the same drive.
How do I know if my system could benefit from more RAM?
Photoshop contains a simple built-in monitor that can help you determine how efficiently the RAM in your system is being used to process your photos. To test the current memory settings, select the Efficiency setting from the pop-up menu of the Status Bar at the bottom of the document window (or the Info palette), and then perform a series of standard editing actions in Photoshop. If only RAM memory is being used during these editing steps, then the Efficiency result displayed will be 100%.
The value actually represents the percentage of time spent performing the operation instead of reading or writing data to the scratch disk. If the value falls below 100%, Photoshop is using the scratch disk in place of RAM and is therefore operating more slowly than if more memory were available. Regular occurrences of values below 95% means that you need to allocate more RAM to Photoshop, close programs running at the same time as Photoshop, or install more RAM memory.
Select Efficiency from the display menu in the Status Bar. Check the values displayed after different processing steps to ensure that they are close to 100%.
3. Set the RAM percentage used by Photoshop
Photoshop shares the RAM on your computer with the operating system (Windows or Mac OS X) and any other programs running at the same time. The percentage designated in the Memory Usage section of the Preferences Performance panel determines the upper amount of RAM memory that can be used by Photoshop. Most new users push this setting as high as possible, some as much as 90%, thinking that this will speed up the processing of their files. But if this allocation is set too high, both the operating system and Photoshop may need to move information from the fast RAM memory to the slower hard-drive memory while processing. This action is called “page swapping,” as the data is moved back and forth between the different memory spaces, and it causes Photoshop to run more slowly.
Use the RAM slider in the Performance section of the Preferences dialog box to adjust the amount of memory allocated to Photoshop.
When adjusting the amount of memory allotted to Photoshop in the Performance panel, it’s best to keep within the ideal range displayed. Check the Efficiency value on the Status Bar to test whether the settings currently being used are optimal. If you do choose to adjust the Memory Usage settings, change them by no more than 5% at a time, and then restart Photoshop and test the new settings before changing them again.
Remember that with Photoshop CS5 running in 32-bit mode, the program can only directly access up to 2.1GB of RAM for Mac or 3GB for Windows—even if more is installed. In contrast, on 64-bit systems with compatible 64-bit hardware, Photoshop CS5 can directly access as much RAM as is installed on your system.
4. Defragment your drives regularly
As images and files are saved and resaved to disk, they tend to become fragmented. This means that rather than the whole file being saved in one continuous space on the hard drive, the information is broken into bits and stored in several locations (wherever there is empty disk space). When the file is reopened, the document is reconstructed from each of the individual pieces. This file fragmentation slows down the opening and saving of files, as well as the running of programs such as Photoshop, if they were fragmented when initially installed. The efficiency of scratch disks is also degraded if the space used for virtual memory is fragmented. You can achieve real performance gains by regularly defragmenting the drives you use for scratch disks, image storage, and application loading.
Both Windows and Mac operating systems have defragmentation utilities built in. Consult your computer’s Help files to ensure that utilities are activated and, if need be, perform a manual defragmentation of all drives to ensure their continued performance.
The Windows Disk Defragmenter utility allows you to analyze and defragment the hard drives installed on your system. Similar utilities are available for Mac computers.
5. Minimize History States
The ability to jump backward and forward through the editing steps stored in the History panel in Photoshop is a very useful feature. Photoshop implements this feature by storing additional copies, called History States, of the image on your hard drive.
A full copy at the original size is stored for every operation you perform that affects the entire image. Smaller changes, like individual paint strokes, require less information per state. The more editing you do, the more hard-drive space will be used for the History States of the document. The History States setting in the Performance panel is set to a default of 20 but can be adjusted from 1 to 1,000, depending on the amount of scratch disk space available and the complexity of your normal image-editing work. If you find that Photoshop is running slowly after you’ve made a few editing changes, then try reducing the number of states. Fewer History States does mean less opportunity to reverse editing changes, but this action frees up memory resources and can bring new life back to a slow-running machine.
The number of History States used by Photoshop can be altered via the History States setting in the Performance section of the Preferences dialog box.
6. Avoid “Out of RAM” errors when running memory-intensive features
Some Photoshop features, such as Content-Aware Scaling, 3D, and Liquify and filters such as the Distort filters are more memory-intensive than others. If when you’re working with these features, Photoshop starts to respond slowly, doesn’t respond, or returns “Out of Memory” or “Out of RAM” errors, then increase the amount of RAM and scratch disk space and close any other programs running at the same time as Photoshop. If the problem persists, then switch to a 64–bit system with more available RAM and scratch disk space.
7. Reduce the number of open files
The more pictures you have open in Photoshop, the more resources your machine is using just to maintain each open file. To speed up processing, make sure that you open (and keep open) only files that are essential for your current editing task.
8. Clear all available memory: Purge Undo, Clipboard, or Histories
The Edit > Purge command can be used to free up RAM space that is being used to store Undo, Clipboard, and Histories entries. Since this command cannot be undone, it should be your last resort when you need to eliminate an “Out of RAM” error during a memory-intensive task.
Use the Edit > Purge command to remove information currently being stored in memory.
9. Run Photoshop by itself
Use the Edit > Purge command to remove information currently being stored in memory.
A simple way to speed up Photoshop is to make sure that no other programs or utilities are running at the same time. After closing unnecessary programs, use your operating system tools to determine which utilities are still running hidden in the background. The golden rule is that if the program or utility is not essential for the editing task, then close the software.
This is especially true if you are using features that rely heavily on the GPU (mainly 3D). Having another application that also relies on the GPU and VRAM open while using these GPU features in Photoshop CS5 will significantly degrade overall performance.
10. Optimize Cache Level and Cache Tile settings
Whenever you make a change to an image onscreen, your computer must redraw the image. The larger the image, the more processing power and time required. To make screen redrawing as fast as possible, Photoshop CS5 uses caching to continuously update a lower resolution version as you work. The default setting is four cache levels, but if you routinely work with images that have large pixel dimensions, you can improve redrawing performance by setting the level higher. Conversely, if you typically work with small-dimension images that contain many layers, you may want to set Cache Level to a level of two. As the cache is also used for other operations, such as the Healing Brush, it is not recommended to set a value of one as this will turn off caching completely, reducing performance in these allied areas.
When Photoshop processes a photo, it splits the picture into smaller image sections called tiles, and it works on each in turn. By default, the size of each tile is 128Kb. You can alter the amount of memory allocated for the processing of each tile via the options in the Cache Tile Size pull-down menu in the Performance panel. Larger tile sizes reduce the amount of time Photoshop takes to process an image, especially on computers with more than 1GB of RAM.
You’ll notice improvements in the speed with which images are drawn to screen when both Cache Level and Cache Tile settings are optimized. To help with accurately setting values, the History & Cache section of the Performance panel in the Preferences dialog box now contains three buttons to help match settings with your work environment. The values set by these buttons will vary depending on the amount of RAM and number of processors in your computer. Click the option that best fits your workflow to set both Level and Tile settings.
Tall and Thin—Best for users working with images with smaller document dimensions and many editing and enhancement layers.
Default—Designed for general use when a user will be working with a variety of document types. This is the default setting.
Big and Flat—Works well with large images and few editing or enhancement layers.
Setting the History and Cache values is easier in Photoshop CS5 thanks to the inclusion of three buttons—Tall and Thin, Default, and Big and Flat—in the Performance section of the Preferences dialog box. Select the option that best matches your workload.
11. Reduce patterns and brush tips
Each custom pattern and brush tip you load increases the overall RAM required to run Photoshop CS5, increasing the scratch disk size in the process. If you load up all the patterns and brush tips that ship with Photoshop CS5, your scratch disk file will grow by hundreds of megabytes. To reduce the total RAM used, minimize the number of patterns and brush tips and reduce the number of patterns used in Layer Styles that use Bevel and Emboss Texture or Pattern Overlay.
12. Optimize GPU settings
With the increasing ability of Photoshop to use of the video card GPU for extra processing power, the Preferences dialog box now includes dedicated GPU settings in both its Performance and 3D sections.
If a suitable video card is installed on your system, it will appear in the GPU Settings area of the Performance section. To enable GPU acceleration, make sure that the Enable OpenGL Drawing option is selected. To fine-tune the card’s performance, click the Advanced Settings button and select Basic, Normal, or Advanced, matching the option with your requirements.
Basic—Uses the least amount of GPU memory to run the most basic OpenGL features when sharing the GPU with other applications or when experiencing slow responsiveness. Select this option if you have other programs running that also use the GPU or if you notice bad screen redraws or slower performance when using GPU-accelerated features.
Normal—Is the default setting. It uses a large amount of GPU memory to support advanced OpenGL features and should be selected if you regularly use the GPU-accelerated features in Photoshop.
Advanced—Uses the same amount of memory as the Normal mode, but enables more advanced features to improve drawing performance. This setting is best when working in 3D or when working extensively with the GPU-accelerated features in Photoshop CS5
Keep in mind that mode changes will only take effect after Photoshop is restarted.
The 3D section of the Performances dialog box contains a VRAM slider similar to the memory control located in the Performance section. Use the slider to determine the upper limit of VRAM available to the Photoshop 3D engine. The total value is a percentage of the overall VRAM available. A setting of 100% will still reserve a portion of the overall VRAM for use with the operating system. Higher values will help with overall 3D performance but may compete with other GPU-enabled applications.
The slider in the 3D section of the Preferences dialog box adjusts the amount of VRAM available to Photoshop.
13. Choose the appropriate Photoshop file type
The slider in the 3D section of the Preferences dialog box adjusts the amount of VRAM available to Photoshop.
The file type you choose will determine both the functions and features that can be saved with the file as well as the maximum size. PSD and PSB files maintain the most functionality but at the cost of file size, especially if the Maximize PSD and PSB File Compatibility option is selected. The maximum image sizes possible in standard Photoshop CS5 documents are as follows:
PSD (Photoshop)—2GB
PSB (Large Document Format)—4EB (Four exabytes equals 4 million terabytes, which is orders of magnitude larger than available hard-drive storage space, but the format has been built to accommodate future innovation.)
TIFF—4GB (Note that most other applications cannot work with TIFF images larger than 2GB.)
Photoshop PDF—10GB (Individual pages are limited to 200×200 inches.)
14. Set the Maximize File Compatibility option
Photoshop CS5 is the 12th version of the software and includes many changes, additions, and enhancements since its initial release. In addition, today many other software applications are capable of opening Photoshop PSD documents, such as Adobe After Effects® CS5 and Adobe Photoshop Lightroom® 3 software. To help ensure that earlier versions of Photoshop or other applications such as Photoshop Lightroom can open your saved files, Photoshop CS5 by default stores a flattened copy of the image within the PSD or PSB document when it is saved. The advantage of this feature is backwards compatibility with Photoshop itself and better integration with other applications, but the tradeoff is larger file sizes and slower opening and saving of documents. By default, Photoshop CS5 will ask if you want to maintain compatibility whenever you save a PSD or PSB file, but this behavior can be adjusted by choosing Photoshop/Edit > Preferences > File Handling. In the File Compatibility section, you can use the menu labeled Maximize PSD and PSB File Compatibility to set Photoshop to either always or never save this extra flattened image within the file.
15. Turn off thumbnail display
Some of the panels in Photoshop CS5 display preview thumbnails of content, such as the Layers, Channels, and Paths panels. As you edit an image, these thumbnails are dynamically updated to reflect the new content. The more layers or paths in a document, the more thumbnails need to be built, drawn, and updated, each requiring system resources. To free up the resources allocated to this task, open the panel menu and choose Panel Options and then select None to turn off thumbnail display.
Select None in the Layers Panel Options dialog box to free up the resources Photoshop uses to draw thumbnail previews.
16. Reduce color bit depth
In Photoshop CS5, the number of functions that can be performed on 16- and 32-bit images has been increased. However, these images require considerably more processing power and hard-drive space than standard 8-bit images. For images destined for output to standard devices or the web, you can use the Image > Mode menu to lower the bit depth to 8 bit for maximum performance. The exception to this general rule is when you are working with 3D images, as the Ray Tracer engine renders at 32-bit color depth. So if you are working with 3D, start with a 32-bit file with a resolution of 72ppi, and when it comes time to output the finished document, use the tone mapping features in Photoshop to reduce the bit depth to 16 or 8 bits.
17. Deselect Export Clipboard
Whenever you exit Photoshop CS5, anything you have cut or copied is placed on the operating system clipboard. The benefit of this feature is that the content is then available to paste into another application, but exporting the image to the clipboard is time-consuming and processor- intensive. If you don’t require or use the system clipboard to copy and paste between Photoshop and other applications, you can turn off this function by deselecting Export Clipboard in the Options area under Photoshop/Edit > Preferences > General. Note that dragging layers or entire images between documents bypasses the clipboard entirely and is more efficient, even if Export Clipboard is enabled.
Deselect the Export Clipboard option in the General section of the Photoshop Preferences dialog box to stop storing copied documents to the operating system clipboard.
18. Adjust or turn off font preview
Each active font on your computer requires system resources. Photoshop CS5 also uses resources to draw previews of each font in the font and style menus in the Character panel and in the Options bar when a Type tool is enabled. To maximize performance, use font management software to activate only the fonts that you need. In addition, you can adjust the size of the font menu previews, or turn off previews, by choosing Photoshop/Edit > Preferences > Type. Under Font Preview Size, use the menu to adjust the size of the previews, or deselect the option to turn them off altogether.
Turning off font previews or selecting a smaller preview size helps reduce the resources used for this task.
19. Optimize image files
Many factors impact the size of your Photoshop CS5 image files, including resolution and pixel dimensions; color depth and mode; number and complexity of layers, channels, and paths; number of Smart Objects; and more. Very large files take longer to open, and they redraw more slowly as you work with them. They also require much more hard-drive space for storage. Ways to optimize image files include:
Minimize file dimensions—Resize the image to the desired size for output rather than working with a very large image and resizing it downward at the end of editing.
Minimize complexity—Merge layers that no longer need to be kept separate, and eliminate channels and paths that are no longer needed. Note that this includes blank layers, which also use significant disk space.
Choose RGB over CMYK—If your images are going to the web rather than offset printing, use the RGB color model. With one less color channel to save and maintain, an RGB image is 25% smaller than an equivalent CMYK image.
Minimize print resolution—Keep your image to the optimal minimum size for the output device, ranging from 72dpi for screen display to 600dpi for high-quality laser printing. Never use a resolution higher than the printing device is capable of outputting.
Start with low-resolution 3D files and resize to suit—When working with 3D content, start with smaller, low-resolution documents such as those generally used for the web. The smaller size will provide better and more responsive performance when manipulating and editing the 3D content. As the 3D components are vector-based imagery, the completed image can be resized nondestructively to a different resolution.
