Windows Vista 32-bit and 64-bit (x86 and x64) Maximum Supported RAM Physical Memory Limit
Windows Vista is by far the most resource hungry and memory usage extensive yet operating system available to date, as has been shown by the high-end system specifications that needed to run Windows Vista properly and efficiently, especially if you intends to enable all advanced Windows Vista features in a Windows Vista Premium Ready PC. One way to run Windows Vista faster is to add and install as many memory or RAM as possible to your desktop or laptop computer. However, don’t buy the memory chips as many as you can even your system can support it, or you have too many money to spare, as there is upper limits on physical memory and virtual memory address space that Windows Vista can support and recognize.
Windows Vista supports up to 4GB RAM virtual memory address range for most editions of 32-bit Windows Vista with the exception of Windows Vista Starter edition, and up to 128GB of physical memory for most editions of 64-bit Windows Vista except Windows Vista Home Basic and Home Premium. Windows Vista Starter edition is not available in 64-bit or x64 version.
| Windows Vista Edition | 32-bit (x86) Windows | 64-bit (x64) Windows |
| Windows Vista Ultimate | 4 GB | 128 GB |
| Windows Vista Enterprise | 4 GB | 128 GB |
| Windows Vista Business | 4 GB | 128 GB |
| Windows Vista Home Premium | 4 GB | 16 GB |
| Windows Vista Home Basic | 4 GB | 8 GB |
| Windows Vista Starter | 1 GB | N/A |
Windows Vista Limits on Maximum Physical and Virtual Memory Address
The maximum supported physical memory on Windows Vista is not to be confused with virtual memory addresses that a Windows Vista can use. Although the Windows Vista 32-bit operating system platform releases can theoretically and technically can use and support more than 4GB of physical memory or RAM by using PAE (Physical Address Extension) to access the memory remapped by the mainboard or motherboard above the 4GB address boundary, however, the x86 version of Windows Vista does not by design support full use of 4GB physically installed RAM, as all 32bit editions of Vista are design on PAE-Kernal to limit to 4GB virtual memory address space, with Vista Starter limits to 1GB.
Since only a maximum of 4GB virtual memory address range is available in Windows Vista, which are sub-divided or allocated some memory address range to manage both the computer’s PCI memory address range (also known as MMIO) which used for system video graphics cards, BIOS, IO cards, networking, PCI hubs, bus bridges, PCI-Express, and RAM, so the amount of available RAM is always less than 4 GB. BIOS takes up about 512 KB, with video or graphic accelerator card needs memory address for at least the amount of memory on the graphics card. Which mean if you have 256 MB VRAM graphic card, at least 256 MB already been used up from your 4 GB memory available to Windows Vista. The net result is that a high performance x86-based computer may allocate 512 MB to more than 1 GB for the PCI memory address range before any RAM (physical user memory) addresses are allocated. So the typical available RAM for the OS will be reduced to between 3 GB and 3.4 GB.
So if you want to fully utilize your physical memory of 4 GB or more in Windows Vista, the only way is to install 64-bit Windows Vista operating system which uses 64-bit addressing enabling virtually the entire amount of installed RAM to be made available on computers that have large address infrastructures (where the entire system has more than 4 GB addressing capabilities via the processor, chipset, physical memory capacity, etc), by moving the virtual memory address range needed by the system PCI, I/O and RAM out of the 4GB address space.
Note that also on 32-bit editions of Windows, applications have 4 gigabyte (GB) of virtual address space available. The virtual address space is divided so that 2-GB is available to the application and the other 2-GB is available only to the system. So if your Vista system unable to use more than 2GB of memory even though 4GB has been installed, try to use 4GT RAM Tuning feature increases the memory that is available to the application up to 3-GB, and reduces the amount available to the system to between 1 and 2-GB, by adding the /3GB switch to the Boot.ini file.
Related Articles
- Limit Maximum TCP Connections to Web Servers
- Windows 7 Supported and Non-Supported Upgrade Paths Test Matrix
- Windows Half-Open Limit Fix (Patch) Free Download to Remove XP, Vista and Server 2003 (32 and 64-bit) TCP 4226 Connection Attempts Limit
- How to Install Windows 7 or Windows Vista on Physical Machine Without DVD Media
- Gmail 20MB Maximum Attachment Size Limit
- Send and Receive Maximum Email Attachment Size Limit of Up To 25 MB in Gmail
- Tweak Windows Vista Virtual Memory (Change or Disable Paging File Size)
- Maximum Windows 7 Specification for Netbooks
- Hack to Install Windows 7, Vista or Server 2008 On Computer or Virtual Machine with Less Than 512 MB RAM Memory
- SLA 2.0 Supported BIOSes for Instant Windows Vista OEM Activation










































June 30th, 2009 22:20
Hi,
The blog seems very usefull, but it turns out that your spelling and grammar skills are very poor. If you are giving advice about a topic that is soo shaded by the rest of the computer’s capabilities, in other words no one actually knows about this stuff unless they’re really into computers, then maybe you should consider making your writing a bit clearer. Again, great advice but I actually had to spend more time trying to figure out your spelling than how to use your advice.
Thanks.
February 28th, 2009 02:56
[...] Maximum RAM supported with 32-bit processor-based system [...]
December 20th, 2008 03:36
The /3GB switch is not for general use. It is intended primarily for use on servers and is usually not recommended for workstations. NOTE: this has nothing whatsoever to do with how much RAM can be used. It changes the virtual address space available to applications to 3GB, leaving 1 GB for the system. Few applications will benefit from this while restricting the system space may impair performance and cause other problems.
If you do not understand this then this setting is not for you.
October 20th, 2008 02:40
[...] Posted by Ronin http://www.mydigitallife.info/2007/0…-memory-limit/ Read that article in case you think about getting vista; Using the full ram only works on 64bit. [...]
October 20th, 2008 02:36
[...] http://www.mydigitallife.info/2007/0…-memory-limit/ Read that article in case you think about getting vista; Getting the full ram only works on 64bit. __________________ "You want to make things right? Too bad. Nothing’s ever right." "Occam’s Razor. The simplest explanation is almost always somebody screwed up." C2D P9500, 9800M GT, 4 GB DDR3 RAM, intel WiFi Link 5300, 15" WSXGA+ [...]
May 16th, 2008 03:55
[...] Originally Posted by Tareith Half-truths without knowing why are dangerous. I think he may want to read about the differences between 32bit and 64bit OS/apps. Read the full document not just the chart Windows Vista Edition 32-bit (x86) Windows 64-bit (x64) Windows Windows Vista Ultimate 4 GB 128 GB Windows Vista Enterprise 4 GB 128 GB Windows Vista Business 4 GB 128 GB Windows Vista Home Premium 4 GB 16 GB Windows Vista Home Basic 4 GB 8 GB Windows Vista Starter 1 GB N/A "So the typical available RAM for the OS will be reduced to between 3 GB and 3.4 GB." Windows Vista 32-bit and 64-bit (x86 and x64) Maximum Supported RAM Physical Memory Limit My Digital… [...]
April 22nd, 2007 02:36
[...] and will yield improved performance, other than allows Windows Vista to take advantage of more than 4GB of RAM memory. However, is it really the [...]