To help Photoshop perform better, it’s always good to give it some finetuning from time to time. The image cache allows Photoshop to increase rendering times of frequently seen areas of an image. In the Memory & Image Cache preferences dialog box, you can set the right balance between speed and performance. 1. If you are a Macintosh user, go to the Photoshop menu and select Preferences -> Memory & Image Cache. As a Windows user, choose Edit -> Preferences and select Memory & Image Cache. If you are in the dialog box from the previous task, you may select Memory & Image Cache from the drop-down menu at the top of the dialog box. 2. The image cache enables Photoshop to increase screen redraw speeds during the editing process by caching, or storing in memory, previews of an image at various zoom levels. As you zoom in or out on the image during editing, it can then pull up the new redraw from the cache rather than reading it from your hard drive. To change the cache settings, enter an integer between 1 and 8 in the Cache Levels text box under Cache Settings. The lower the cache level, the slower the image window redraws. 3. To set a good balance of speed and quicker rendering for Cache Level, stick with the default value, which appears to offer a solid balance of speed and quicker rendering. Setting the cache to a value of 1 disables it—you wouldn’t want to set it that low unless you always work at 100 percent magnification. Setting the cache at its highest setting of 8 causes it to store more preview sizes and would probably not be necessary unless you are working on an extremely large file. 4. Select Use Cache for Image Histograms if you want Photoshop to display histograms faster; however histograms are based on a sampling of pixels and not all of the pixels. 5. Under Memory Usage you can specify the percentage of maximum RAM to be used by Photoshop. However, you should never allocate more than 90% to Photoshop, or you will probably cause your system to crash. 6. Leave the maximum memory used by Photoshop setting at the default 50% at first. While working on images, you can check the Efficiency setting in the status bar from time to time. If you see it dropping below 100%, you can increase the allocation of memory to Photoshop incrementally until it goes back to 100%. 7. After resetting the memory allocation, you’ll need to restart Photoshop in order for the new settings to be active.