Windows 7 64-bit Loses RAM (System Memory)

Last Updated on Thursday, 17 December 2009 01:11 Written by Mire_B Thursday, 17 December 2009 01:11

The system memory reported as (usable) in the System Information box in 64-bit Windows 7 may be less than the amount of installed RAM

On a 64-bit version of Windows 7, if your computer has an amount of random-access memory (RAM) installed, the amount of system memory reported in the System Information dialog box in Windows 7 may be less than the amount of installed RAM.

For example, the System Information dialog box may report (7.1 GB Usable) of system memory on a computer that has 8 GB (8,192 MB) of memory installed. Note You can access the System Information dialog box on Windows 7-based computers in any of the following ways:

· Click Start, type System in the Search programs and files box, and then click System under Control Panel.

· Double-click System in Control Panel.

· Click Start, right-click Computer, and then click Properties.

On the System Properties window, look at the Installed memory (RAM): entry under System

To View the installed RAM and how it’s allocated in Windows, see the physical Memory section in the Resource Monitor. To do this, follow these steps:

· Click Start, type Resource Monitor in the Search programs and files box, and then click Resource Monitor under Programs.

· Click the Memory tab and see the Physical Memory section on the bottom of the page.

This is expected behavior on Windows 7-based computers. The reduction in available system memory depends on the devices that are installed in the computer and the amount of memory reserved by those devices, the motherboards ability to handle memory and the BIOS version and settings and other system configuration settings. Note When the physical RAM installed on a computer equals the address space that is supported by the chipset, the total system memory that is available to the operating system is always less than the physical RAM that is installed. For example, consider a computer that has an Intel 975X chipset that supports 8 GB of address space. If you install 8 GB of RAM, the system memory that is available to the operating system will be reduced by the PCI configuration requirements. In this scenario, PCI configuration requirements reduce the memory that is available to the operating system by an amount that is between approximately 200 MB and approximately 1 GB. The reduction depends on the configuration.

There are several additional situations that might cause the amount of usable RAM listed in the System Properties to be less than expected. These issues and possible solutions are listed below:

Memory has been reserved by Hardware

· Memory can be reserved by video cards and other devices; this is listed as Hardware Reserved. The amount of Hardware Reserved RAM is listed on the Memory Tab of the Resource Monitor.

System Configuration settings may be incorrect

· If you upgraded a 64-bit version of Windows it’s possible that the Maximum memory setting was enabled on your system and was transferred to the upgraded version. This setting sets the maximum memory to 4GB or below. You can disable this setting by clicking on Start, and typing msconfig in the Search programs and files box, and then click msconfig from the Programs list. In the System Configuration window click the Boot tab, click Advanced options…, and uncheck Maximum memory:, click OK, close the System Configuration window, close all other applications and then reboot your computer.

Your system BIOS may be out dated

· Your system BIOS may not have been updated, if you have an older computer, your system may not be unable to access all of the installed RAM. Update your BIOS to the latest version by either browsing the web site of your computer manufacturer or contact the computer manufacturer for assistance and download any available BIOS updates for your computer.

BIOS settings may be incorrect

· Check your BIOS settings to see if memory remapping has been enabled, memory remapping gives Windows access to more memory. You can enable the memory remapping feature in your BIOS by booting to the system setup. See the Users Guide for your computer for instructions on how to boot to Setup on your computer. The name for the memory remapping feature may be different for different hardware vendors. This can be listed as memory remapping, memory extension or other similar descriptions.

· Check your BIOS settings to see how much memory you may have allocated to AGP video aperture? This is memory that your SYSTEM is sharing with your video card that is used for texture mapping and rendering. This memory would not be utilized by your system, as it is locked by your video card. You can adjust your AGP video aperture size in the BIOS, standard settings are 32Mb, 64Mb, 128MB, Auto. For troubleshooting purposes you can adjust this setting in the BIOS, and then reboot your computer and then check the amount of usable memory. Test each setting to see which offers the best results.

There may also be issues with the physical RAM installed in your computer

You may have bad memory modules

The physical memory modules installed in your computer can be bad. You can test this by shutting down and unplugging the computer, swapping the order of the memory and then rebooting the computer.

Memory Arrangement:

· Check your users guide to see what order your memory modules should be inserted into the memory slots, some systems require using specific slots when not using all available slots. (Example: some systems that have 4 slots available require you to use slots 1 and 3 instead of 1 and 2 when only using 2 memory modules)

Memory Standoff Cards:

· Are you using memory standoff cards, (a card inserted into the memory slot that holds multiple memory modules)? This allows you to utilize more memory modules than the system was originally designed for. Some systems may require specific configurations for this scenario.