Maximum RAM Supported By Windows
Last Updated: 18 Feb 2008 / Prior Update: 21 Mar 2007
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*** PLEASE NOTE: Link(s), If Provided, May Be Wrapped ***
Various versions of Windows have different maximum RAM
that they can support. All limits greater than 4GB for
32-bit operating systems assume that PAE is enabled, as do
application memory sizes of over 2GB:
MAXIMUM MEMORY in GB (or TB)
OPERATING SYSTEM TOTAL /per App / VMEM / CPUs
============================================================
• WINDOWS 95/98/ME ............ 2GB / 2GB / 4GB / 1
• NT WORKSTATION .............. 4GB / 2GB / 4GB / 2
• NT SERVER ................... 4GB / 2GB / 4GB / 4
• NT ENTERPRISE SERVER ........ 4GB / 3GB / 4GB / 8
• WIN 2000 PROFESSIONAL ....... 4GB / 2GB / 4GB / 2
• WIN 2000 SERVER ............. 4GB / 2GB / 4GB / 4
• WIN 2000 ADV SERVER ......... 8GB / 7GB / 4GB / 8
• WIN 2000 DATA CENTER ........ 64GB / 15GB / 4GB / 32
• WIN XP STARTER .............. 512MB / 2GB / 4GB / 1
• WIN XP HOME ................. 4GB / 2GB / 4GB / 1
• WIN XP PROFESSIONAL ......... 4GB / 2GB / 4GB / 2
• WIN 2003 WEB SERVER ......... 2GB / 2GB / 4GB / 2
• WIN 2003 STANDARD SERVER .... 4GB / 2GB / 4GB / 4
• WIN 2003 ENTERPRISE ......... 32GB / 3GB / 4GB / 8
• WIN 2003 ENTERPRISE SP1...... 64GB / 3GB / 4GB / 8
• WIN 2003 DATA CENTER ........ 64GB / 3GB / 4GB / 32
• WIN 2003 DATA CENTER SP1..... 128GB / 3GB / 4GB / 32
• VISTA STARTER ............... 1GB / 2GB / 4GB / 1
• VISTA HOME BASIC ............ 4GB / 2GB / 4GB / 1
• VISTA HOME PREMIUM .......... 4GB / 2GB / 4GB / 1
• VISTA BUSINESS .............. 4GB / 2GB / 4GB / 2
• VISTA ENTERPRISE ............ 4GB / 2GB / 4GB / 2
• VISTA ULTIMATE .............. 4GB / 2GB / 4GB / 2
• WIN 2008 WEB SERVER ......... 4GB / 2GB / 4GB / 2
• WIN 2008 STANDARD ........... 4GB / 2GB / 4GB / 4
• WIN 2008 ENTERPRISE ......... 64GB / 3GB / 4GB / 8
• WIN 2008 DATACENTER ......... 64GB / 3GB / 4GB / 32
--- ITANIUM (IA64) EDITIONS OF WINDOWS
-------------------------------------------------------------
• WIN XP PROFESSIONAL IA64 .... 64GB / 8TB / 16TB / 2
• WIN 2003 ENTERPRISE IA64 .... 64GB / 8TB / 16TB / 8
• WIN 2003 DATA CENTER IA64 ... 512GB / 8TB / 16TB / 32
• WIN 2008 IA64 ............... 2TB / 8TB / 16TB / 64
--- AMD64/EM64T (x64) EDITIONS OF WINDOWS
-------------------------------------------------------------
• WIN XP PROFESSIONAL ......... 128GB / 8TB / 16TB / 2
• WIN 2003 STANDARD ........... 16GB / 8TB / 16TB / 4
• WIN 2003 STANDARD SP1 ....... 32GB / 8TB / 16TB / 4
• WIN 2003 ENTERPRISE ......... 64GB / 8TB / 16TB / 8
• WIN 2003 ENTERPRISE SP1 ..... 1TB / 8TB / 16TB / 8
• WIN 2003 ENTERPRISE SP2 ..... 2TB / 8TB / 16TB / 8
• WIN 2003 DATA CENTER ........ 512GB / 8TB / 16TB / 64
• WIN 2003 DATA CENTER SP1 .... 1TB / 8TB / 16TB / 64
• WIN 2003 DATA CENTER SP2 .... 2TB / 8TB / 16TB / 64
• VISTA HOME BASIC ............ 8GB / 8TB / 16TB / 1
• VISTA HOME PREMIUM .......... 16GB / 8TB / 16TB / 1
• VISTA BUSINESS .............. 128GB / 8TB / 16TB / 2
• VISTA ENTERPRISE ............ 128GB / 8TB / 16TB / 2
• VISTA ULTIMATE .............. 128GB / 8TB / 16TB / 2
• WIN 2008 WEB SERVER ......... 32GB / 8TB / 16TB / 2
• WIN 2008 STANDARD ........... 32GB / 8TB / 16TB / 4
• WIN 2008 ENTERPRISE ......... 2TB / 8TB / 16TB / 8
• WIN 2008 DATACENTER ......... 2TB / 8TB / 16TB / 64
RESOURCE LIMITS IN 64-BIT WINDOWS
• http://support.microsoft.com/?KBID=294418
MEMORY TESTING TOOLS
• Memory Tester .......... http://www.memtest86.com/
• SIMM Tester ............ http://www.simmtester.com/PAGE/products/doc/docinfo.asp
• Microsoft Memory Diag .. http://oca.microsoft.com/en/windiag.asp
WHITEPAPERS & TECH DOCUMENTS
• http://msdn2.microsoft.com/en-us/isv/bb190528.aspx
• http://zone.ni.com/devzone/cda/tut/p/id/5709
• http://www.msexchange.org/tutorials/why-64-bit-good-e12.html
• http://msdn2.microsoft.com/en-us/library/aa366778.aspx
• http://www.microsoft.com/windowsserver2008/sysreqs.mspx
• http://www.microsoft.com/windows/products/windowsvista/editions/64bit.mspx
• http://technet.microsoft.com/en-us/windowsserver/bb430827.aspx
• http://www.microsoft.com/windowsserver2003/evaluation/sysreqs/default.mspx
• http://www.microsoft.com/windowsserver2003/techinfo/overview/x64benefits.mspx
• http://www.microsoft.com/windowsserver2003/64bit/x64/overview.mspx
• http://www.microsoft.com/windowsserver2003/evaluation/overview/family.mspx
• http://www.microsoft.com/windowsserver2003/evaluation/features/compareeditions.mspx
• http://www.microsoft.com/windowsxp/64bit/overview.mspx
• http://support.microsoft.com/?KBID=294418
• http://support.microsoft.com/?KBID=181594
• http://support.microsoft.com/?KBID=283247
• http://www.microsoft.com/windows2000/en/datacenter/help/newvlm0.htm
• http://www.microsoft.com/windows2000/en/datacenter/help/address_windowing_extensions.htm
• http://msdn.microsoft.com/msdnmag/issues/01/12/XPKernel/XPKernel.asp
WINDOWS 95/98/ME ISSUES
• http://www.techtv.com/screensavers/windowstips/story/0,24330,3337233,00.html
• http://www.computerhope.com/jargon/v/vcache.htm
• http://www.dewassoc.com/support/win98/win9x_512memory.htm
• http://tweakhomepc.virtualave.net/memory/vcache95.html
• http://support.microsoft.com/?KBID=253912
• http://support.microsoft.com/?KBID=311871
• http://support.microsoft.com/?KBID=304943
• http://support.microsoft.com/?KBID=184447
WINDOWS 9X/ME RESOURCE USAGE
• http://www.forrestandassociates.co.uk/pcforrest/resources.html
PERSONAL NOTES
• Feb 2008: Added memory information for Vista and
Windows Server 2008, along with the SP1 & SP2
updates of Windows 2003.
• Apr 2006: Added a link related to Exchange v12 (E12)
which will be 64-bit only.
• May 2005: Updated info to deal with Windows for x64
systems from AMD (AMD64) and Intel (EM64T) which are
not compatible with the Itanium family.
• Stats for total CPUs supported in Windows do not
include HyperThreading, which is available to 2000
and later.
• Win9x/ME supports 2GB RAM, but requires some config
changes to properly address over 512MB in many cases.
• It has been hard to find the maximum virtual memory
supported by various editions of Win2K and XP
• In NT/2000/XP, each app can address an entire 2GB as
its memory space. This is regardless of how much
RAM you actually have in the system. The more RAM
you have, the less likely it is that your apps will
have to make use of virtual memory while being used.
• Win9x/ME is best served by no more than 256MB RAM,
unless you're doing something really RAM intensive,
and you would be much better off with Win2K/XP in
such a scenario.
• Win2K/XP can run decently with 128MB RAM, but for
even a moderate user, 256MB will bring tremendous
benefit, and 384MB should be considered the minimum
for any serious computer user.
• The specs for 64-bit Windows.NET are based on RC1
and are subject to change for the Release Version.
• Initially, Windows 2003 Server, Standard Edition was
to have only support for 2 CPUs. This has been
restored to 4 CPUs, as in previous versions of
Windows Server.
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