Applies to: @RISK, all versions

Should I change my Windows virtual memory settings for use with @RISK simulations?

 

Answer
Possibly — especially if you run large simulations.

By default, Windows manages virtual memory automatically. However, when left on its own, Windows will not increase virtual memory beyond:

• 3× your physical RAM, or

• 4 GB if you have less than 1.33 GB of physical RAM

For large @RISK simulations, this limit may be too low, and System managed virtual memory may not be the best choice.

Recommended approach

• Set your page file size (virtual memory) to at least 3× physical RAM, plus extra space for other programs.

• Do not make it so large that your disk has very little free space — that can slow Windows performance.

• Set the initial and maximum size to the same value so Windows doesn’t waste time resizing the page file during simulation runs.

How to set virtual memory manually

1. Open System Properties

• Windows 7 / 8 / 10 / 11
  Right-click Computer or This PC → Properties → Advanced system settings

• Windows XP
  Control Panel → System

2. Open performance settings

• Go to the Advanced tab

• Under Performance, click Settings

• Select the Advanced tab

• Under Virtual memory, click Change

3. Set a custom size

• Uncheck Automatically manage paging file size for all drives (if present)

• Select Custom size

• Enter the same value for Initial size and Maximum size

• Click OK to close all dialogs

Windows will prompt you if a reboot is required.

 

Related Article:

Memory Used by @RISK Simulations