Vista virtual memory management

Only core parts of the operating system kernel bypass this address translation and use real memory addresses directly. Virtual memory is always being used, even when the memory that is required by all running processes does not exceed the volume of RAM that is installed on the system. In the default Windows configuration, 2 gigabytes GB of this virtual address space are designated for the private use of each process, and the other 2 GB is shared between all processes and the operating system.

Typically, applications for example, Notepad, Word, Excel, and Acrobat Reader use only a fraction of the 2 GB of private address space. The operating system assigns RAM page frames only to those virtual memory pages that are being used.

PAE does not change the size of the virtual address space which remains at 4 GB , but just the volume of actual RAM that can be addressed by the processor. The translation between the bit virtual memory address that is used by the code that is running in a process and the bit RAM address is handled automatically and transparently by the computer hardware according to translation tables that are maintained by the operating system.

Any virtual memory page bit address can be associated with any physical RAM page bit address. The following list describes how much RAM the various Windows versions and editions support as of May :. RAM is a limited resource, whereas for most practical purposes, virtual memory is unlimited. There can be many processes, and each process has its own 2 GB of private virtual address space. When the memory being used by all the existing processes exceeds the available RAM, the operating system moves pages 4-KB pieces of one or more virtual address spaces to the computer's hard disk.

This frees that RAM frame for other uses. In Windows systems, these paged out pages are stored in one or more files Pagefile. There can be one such file in each disk partition. The location and size of the page file is configured in System Properties click Advanced , click Performance , and then click the Settings button. Users frequently ask how big should I make the pagefile?

There is no single answer to this question because it depends on the amount of installed RAM and on how much virtual memory that workload requires. If there is no other information available, the typical recommendation of 1. On server systems, you typically want to have sufficient RAM so that there is never a shortage and so that the pagefile is not used.

On these systems, it may serve no useful purpose to maintain a large pagefile. On the other hand, if disk space is plentiful, maintaining a large pagefile for example, 1. On any computer system, as the load increases the number of users, the volume of work , performance decreases, but in a nonlinear manner. Scroll down the right-hand column and left-click on About. Left-click on System. Press the letter Y to select System.

Under Device specifications , make a note of how much installed RAM your computer has. You will need this for the paging file calculation. Scroll down the right-hand column and left-click on the link labeled Advanced system settings. The System Properties dialog box will appear. The Advanced tab should be active.

If not, just left-click on it to bring it up. Left-click on the Settings Left-click on the Advanced tab of the Performance Options dialog box. Left-click on the Change Deselect the Automatically manage paging file size for all drives checkbox.

Select the drive you want to manage the paging file on. Select Custom size and enter the initial size and maximum size using the calculation shown above. Left-click on the Set button. Left-click on the OK button. Tags : virtual memory. Using Virtual Machines to run old programs in Windows 7 How to run older software in a virtual machine inside of Windows 7. Free computer diagnostics Repairing a PC can sometimes be expensive.

Check out our reviews Google Yelp Yahoo! Merchant Circle Superpages. Customer service is 1 Here at Geeks in Phoenix , we take pride in providing excellent customer service. System virtual address VA space on bit systems can become exhausted due to fragmentation. Several registry keys can be used to configure memory limits on bit systems that experience this issue. System VA space on bit systems is not subject to exhaustion by fragmentation; therefore, these keys have no effect on bit systems.

For bit systems, these memory management registry keys must be explicitly created under the following registry key:. For default memory and address space limits on both bit and bit systems, see Memory Limits for Windows Releases.

The following table describes the memory management registry keys that can be used to configure memory limits on bit systems. The default is 0, which means no limit is enforced.