Changing Memory and Cache Settings in Photoshop

The perennial question: How much memory does Photoshop require? The perennial answer: As much as you can cram into your computer! Memory is so inexpensive right now there’s no excuse for not having at least 512MB of RAM, and more is even better if you’re using an operating system that can handle extra memory efficiently, such as Windows XP and Mac OS X.

When you’ve crammed your RAM, you’ll want to make sure Photoshop can use as much as you can spare. You can use the Memory & Image Cache Preferences dialog box to allocate your memory.

Managing memory
Here’s how to allocate RAM:
1. Choose Edit➪Preferences➪Memory & Image Cache.
The Memory & Image Cache Preferences dialog box opens.
2. In the Memory Usage area, change the Maximum Used by Photoshop parameter.
Use a value of 50 to 80 percent, depending on how much memory you have to waste. Allocating more to
Photoshop reduces the RAM for other applications, so if you have other programs that need lots of memory, choose a prudent value.
3. Click OK to apply the option.
4. Exit Photoshop and relaunch the program to activate the new setting.

Setting aside memory for storing screen images
You can also set aside the amount of memory for storing screen images in the Memory & Image Cache dialog box, to speed up redraws of a reduced-view image on your screen as you make changes. You have two options. You can specify the number of copies of your image stored in memory, from the default value of 4 up to 8 levels. You can also set aside cache memory for drawing histograms (brightness graphs produced by the Levels command) if you use histograms frequently.