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I have a problem with user space on XP. I have a machine with 3GB RAM and my application needs more memory. One solution would be increase the RAM to 4GB and switch on the 3GB Switch.

Right now, I am in remote place and I don't have any RAM.

Any solution to increase the user space?

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migrated from Jan 10 '12 at 15:50

This question came from our site for professional and enthusiast programmers.

Is this XP 64bit or 32bit? What is the application that needs more User Space? Is User Space the same as RAM? – music2myear Jan 10 '12 at 15:59
Crazy idea: run a virtual machine with 4GB memory. BTW what is the software you're using that actually needs more then 2GB virtual memory? BTW2 I am not sure you need 4GB memory to use the /3GB switch. The switch just changes the boundary between user and system space. If your program actually used up all 3GB, parts of it will just be paged to disk as usual. – Jan 10 '12 at 16:10
If the OP is asking about 4GT (and I think he or she is), then 32-bit is implied. The question could benefit from some editing for clarification, particularly since it got moved from StackOverflow. – afrazier Jan 10 '12 at 16:11

You can increase your page file size, or let Windows manage it. You can also turn down the amount of RAM used by other system resources in the BIOS.

To make sure your Page File is set to optimal settings: Open the Control Panel and go to System Properties. On the Advanced tab, in the Performance section, click the Settings button. In the Performance Options dialog, select the Advanced tab and in the Virtual Memory section click the Change button. In the Virtual Memory dialog, is the Paging File Size set to System Managed? If so, that should be best. If you want, though, you could set a custom size based on the application needs.

To free up more memory from other hardware resources: Open your BIOS settings by rebooting your computer and following the instructions on the POST screen. If you have integrated graphics, turn down the amount of memory assigned to graphics to the lowest possible setting.

If these do not work, your application is either not capable of running on a system with only 3GB RAM, or when it refers to User Space it is not talking about RAM. In this case check your HDD to see if it is running out of space and use a program such as CCleaner (by Piriform) to free up space on your HDD.

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You can still turn on 4-Gigabyte Tuning on your XP system and then set the IMAGE_FILE_LARGE_ADDRESS_AWARE flag on your executable. 4GT only affects the user/kernel split of virtual address space on 32-bit systems, it doesn't have anything to do with the amount of RAM in your system.

Alternatively, you can attempt to modify your application to use less RAM. Depending on your constraints, that might be more worthwhile. On your current system with 3GB of RAM, you're going to end up severely RAM constrained (and probably start heavy swapping) if you use 4GT.

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Virtual memory allows the system to use hard disk space to store information normally stored in RAM. Windows XP manages virtual memory by using a paging file.

You specify the minimum and maximum size of this file.

If the size is different from the default in Windows XP, applications may return errors. However, some applications may require a non-default size for the paging file.

Change the size only if other applications aren't adversely affected.

To set the paging file to the default size:

Note: You must be logged on as an administrator to change the size of the paging file.

Quit all applications.

  1. Choose Start > Control Panel > System.

  2. Click the Advanced tab, and then click Settings in the Performance area.

  3. Click the Advanced tab, and then click Change in the Virtual Memory area.
  4. From the Drive list, select a hard-disk partition that has free space equal to at least three times the amount of the computer's installed RAM. To determine the amount of space available on a hard-disk partition, click the drive letter; the amount of space available appears in the Paging File Size For Selected Drive area.
  5. In the Initial Size box, enter a value equal to one and a half times the amount of the computer's installed RAM.
  6. In the Maximum Size box, enter a value equal to twice the amount of the Initial Size value.
  7. Click Set, and then click OK to close the Virtual Memory dialog box.
  8. Click OK to the alert "The changes you have made require you to restart your computer."
  9. Click OK to close the Performance Options dialog box, and then click OK to close the System Properties dialog box.
  10. Click Yes in the System Settings Change dialog box. Windows will then restart.
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