Microsoft KB Archive/181862

= Specifying Amount of RAM Available to Windows Using MaxPhysPage =

Article ID: 181862

Article Last Modified on 1/22/2007

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APPLIES TO


 * Microsoft Windows Millennium Edition
 * Microsoft Windows 95
 * Microsoft Windows 98 Standard Edition

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This article was previously published under Q181862



If this article does not describe your hardware-related issue, please see the following Microsoft Web site to view more articles about hardware:

http://support.microsoft.com/default.aspx/w98?sid=460



SUMMARY
This article contains a table of MaxPhysPage values you can use to limit the amount of random access memory (RAM) available to Windows.



MORE INFORMATION
To use the MaxPhysPage entry to specify the amount of RAM that is available to Windows, add the following line in the [386Enh] section of the System.ini file

MaxPhysPage=

where is a hexidecimal number that determines the number of memory pages available to Windows. A page is 4096 bytes of RAM for 486 and Pentium processors.

When the MaxPhysPage entry is used, the following formula is used to determine the amount of RAM available to Windows:

  4096 X MaxPhysPage (decimal) = Amount of RAM available to Windows in bytes

Therefore, to limit Windows to 32 MB of memory, use the following formula to determine the MaxPhysPage entry:

  (32 * 1048576) / 4096 = 8192 (decimal) or 02000 (hexadecimal)

NOTE: One megabyte is 1,048,576 bytes.

The following table list some common RAM amounts and the corresponding MaxPhysPage entry:

  Amount of RAM available to Windows (MB) (Bytes)           MaxPhysPage entry --  960                        1,006,632,960     MaxPhysPage=3C000 896                         939,524,096     MaxPhysPage=38000 832                         872,415,323     MaxPhysPage=34000 768                         805,306,368     MaxPhysPage=30000 704                         738,197,504     MaxPhysPage=2C000 640                         671,088,640     MaxPhysPage=28000 576                         603,979,776     MaxPhysPage=24000 512                         536,870,912     MaxPhysPage=20000 448                         469,762,048     MaxPhysPage=1C000 384                         402,653,184     MaxPhysPage=18000 320                         335,544,320     MaxPhysPage=14000 256                         268,435,456     MaxPhysPage=10000 224                         234,881,024     MaxPhysPage=0E000 192                         201,326,592     MaxPhysPage=0C000 160                         167,772,160     MaxPhysPage=0A000 128                         134,217,728     MaxPhysPage=08000 96                         100,663,296     MaxPhysPage=06000 88                          92,274,688     MaxPhysPage=05800 80                          83,886,080     MaxPhysPage=05000 72                          75,497,472     MaxPhysPage=04800 64                          67,108,864     MaxPhysPage=04000 56                          58,720,256     MaxPhysPage=03800 48                          50,331,648     MaxPhysPage=03000 40                          41,943,040     MaxPhysPage=02800 32                          33,554,432     MaxPhysPage=02000 24                          25,165,824     MaxPhysPage=01800 16                          16,777,216     MaxPhysPage=01000 12                          12,582,912     MaxPhysPage=00C00 08                           8,388,608     MaxPhysPage=00800

For additional information about MaxPhysPage, please see the following Articles in the Microsoft Knowledge Base:

Article-ID: 134503

TITLE : Parity Error Messages May Indicate Bad Memory

Article-ID: Q83436 83436

Title : Windows 3.1 Resource Kit SYSTEM.INI [386ENH] Section M-Z

Additional query words: HWMEM how to

Keywords: kbdiskmemory kbenv kbhowto KB181862

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