When your computer does not have enough memory to
perform all of its functions, Windows and your programs can stop
working. To help prevent data loss, Windows will notify you when your
computer is low on memory. Other signs of low memory include poor
performance and screen problems. You can also check the Event Viewer and
the Windows Reliability and Performance Monitor.
Your computer has two
types of memory: random access memory (RAM), also known as physical
memory; and virtual memory, also known as a paging file. All programs
use RAM, but when there is not enough RAM for the program you’re trying
to run, Windows temporarily moves information that would normally be
stored in RAM to the virtual memory.
Virtual memory is disk
space that acts like RAM, which allows the operating system to load more
programs and data. Parts of all the programs and data to be accessed
are constantly swapped back and forth between RAM and disk so that the
virtual memory looks and acts like regular RAM. This is beneficial to
the user because disk memory is much cheaper than RAM.
The RAM and virtual memory are broken down into chucks called pages,
which are monitored by the operating system. When the RAM becomes full,
the virtual memory system copies the least recently used programs and
data to the virtual memory. Because this frees part of the RAM, it then
has room to copy something else from virtual memory, load another
program, or load more data. Windows Vista calls the virtual memory a
paging file.
If you have low memory, you should consider
To determine how much RAM
your system has, you can use the Welcome Center, Task Manager, or the
System Information. Open System Information, and then follow these
steps:
1. | Click the Start button and select All Programs
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2. | Select Accessories, and then select System Tools.
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3. | Select System Information. The total amount of RAM is listed under Total Physical Memory.
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Windows Vista does a much
better job of managing virtual memory than earlier versions of Windows.
Windows Vista will set the minimum size of the paging file at the amount
of RAM installed on your computer plus 300 MB and the maximum size at
three times the amount of RAM installed on your computer. If you want to
manually manage virtual memory, use a fixed virtual memory size in most
cases. To do this, set the initial size and the maximum size to the
same value. This ensures that the paging file is consistent and can be
written to a single contiguous file (if possible, given the amount of
space on the volume).
Alert
A
high value for pages/sec counter in Performance Monitor most likely
means that you are low on physical memory because pages/sec shows how
often it has to access the paging file.
To manually configure virtual memory, follow these steps:
1. | Click Start, and then click Control Panel.
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2. | In the Control Panel, click the System and Maintenance category heading link.
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3. | Click System.
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4. | In
the System Console, click Change Settings under Computer Name, Domain,
and Workgroup Settings. Or, click Advanced System Settings in the left
pane.
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5. | Click the Advanced tab in the System Properties dialog box.
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6. | Click Settings in the Performance section to display the Performance Options dialog box.
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7. | Click the Advanced tab, and then click Change to display the Virtual Memory dialog box.
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8. | Clear the Automatically Manage Paging File Size for All Drives check box.
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9. | Under Drive Volume Label, click the drive that contains the paging file you want to change.
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10. | Click
Custom Size, enter a new size in megabytes in the Initial Size (MB) or
Maximum Size (MB) box, click Set, and then click OK.
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Increases in size usually
do not require a restart, but if you decrease the size, you must
restart your computer for the changes to take effect. We recommend that
you don’t disable or delete the paging file.
