The preferences settings for Photoshop are located under the Edit > Preferences menu. Here you will fi nd a series of settings that allow you to adjust the default workings of the program. To change or allocate scratch disks select the Performance or Plug-Ins & Scratch Disks option.

The Performance dialog has settings to allocate all the hard disks you have installed as extra RAM. It is best not to use the same location for Windows/Mac OS virtual memory. It is also worth selecting your fastest drive fi rst as the extra speed will also help increase performance.

You can also allocate the amount of RAM set aside specifi cally for Photoshop in this dialog. With the scratch disks now set up click OK to close the window and then quit Photoshop as the changes will not take effect until you restart the program.