Recommended reading

Vista Workshop: More RAM, More Speed

Features
By published

Supported Memory Size - Windows Vista And Windows XP

Regardless of which version of Windows you are using, all 32 bit systems are limited to a maximum of 4 GB of RAM. The only exceptions to this rule are the Starter Editions, which are primarily targeted at developing nations.

Swipe to scroll horizontally
Memory Limit
Windows Vista32 bit64 bit
Ultimate4 GB128 GB
Enterprise4 GB128 GB
Business4 GB128 GB
Home Premium4 GB16 GB
Home Basic4 GB8 GB
Starter1 GB-

There is only a single 64 bit version of Windows XP, which is identical in feature set with Windows XP Professional. From a technical perspective, it is built around the Windows 2003 Server kernel (Version 5.2).

Swipe to scroll horizontally
Memory Limit
Windows XP32 bit64 bit
Professional4 GB128 GB
Home4 GB-
Starter Edition512 MB-
TOPICS
23 Comments Comment from the forums
  • anonymous x
    Crazy
    Nice article!
    Reply
  • trifler
    We need to see benchmarks comparing Vista with 2MB, 4MB, and 8MB. I can't tell my boss that the new high-end computers should have 8MB without some numbers.
    Reply
  • I think meant GB not MB there Trifler... 8MB of ram is not very much... and a "high-end computer" should have at least 2GB of RAM for a 32-bit system, and is OS dependant for 64-bit systems... vista depends on the ver you use as to how much ram is max.
    I have 1 GB of RAM and am using 80% after a normal boot (plus a few non-essential apps... but they make doing things easier
    Reply
  • SkyPRZ
    There is a "test setup" but not followed by any test but directly by the conclusion.
    Did I miss something?
    Nevertheless I've already built a system with Vista 64 & 8GB ram few weeks ago and wanted the test to comfort decisions I made.
    Reply
  • trifler
    Bleh I meant GB not MB in my earlier comment...
    Reply
  • master9716
    with 2 gigs of ram my 64bit runs ultra fast compared to 32bit , I have 3 hdds quad 6600. it should be the otherway around though . On my laptop with 1.5 gigs vista basic runs prety bad I will reinstall see what happens . We need to see some load time benchmarks !!! eventhough this is an old article
    Reply
  • Darthb0b0
    on page 7, how are you changing the amount of ram a particular app is using? is this only applicable to 64-bit windows, or could you also change this with 32-bit?
    Reply
  • Darthb0b0
    One other thing. on page 5 you say that w/4gb of ram it has no benefit to go to 64 bit due to the larger memory foot print required - essentially eating up the extra memory. The extra system memory used is 757 - 549 = 208. Yet the extra addressable memory gained is 4096 - 3581 = 515. The difference is still a net gain of 307mb of ram. Or am I missing something?

    Also, is the reason that only 3.5GB is available in the 32-bit environment due to the 512mb video card and MMIO? If so, what will happen in a 32 or 64 bit system if you have a video setup with 2gb of video ram? Will you only have 2GB of main memory available?
    Reply
  • Darthb0b0
    One answer found:

    Significant chunks of address space below 4GB (the highest address accessible via 32-bit) get reserved for use by system hardware:

    • BIOS – including ACPI and legacy video support

    • PCI bus including bridges etc.

    • PCI Express support will reserve at least 256MB, up to 768MB depending on graphics card installed memory

    Reply
  • Darthb0b0
    Reply