Maxium Program Size in 64-bit Vista?

[Guest David F]

My understanding is that the maximum program size under Vista 32 is 2 GB (is

that RAM or RAM and virtual memory?).

 

1. What is maximum *physical addressable RAM* for a single 32-bit

processes?

2. What is maximum *virtual address space* for a single 32-bit processes?

3. What is maximum *physical adressable RAM* for a single 64-bit process in

Vista Business 64?

4. What is the maximum virtual address space for a single 64-bit process in

Vista Business 64?

TIA.

[Guest Chuck Walbourn [MSFT]]

Re: Maxium Program Size in 64-bit Vista?

 

Because Windows is a virtual memory OS, the process limit is based on

virtual address space, not physical RAM. The physical RAM limits are tied to

the OS itself.

 

32-bit versions of Windows XP and Vista are limited to 4 GB of physical RAM,

although most motherboards & BIOSes don't really expose the full 4 GB. The

best I've seen is 3.25 GB physical RAM visible with 4 GB installed. 64-bit

versions of Windows XP and Vista support more, and it depends on the exact

SKU as to how much, but ranges from 4 GB to 128 GB or more.

 

A standard 32-bit process can address up to 2 GB of virtual address space.

Typically this means at most 2 GB of physical RAM, although a fair bit less

due the fact that virtual address space is used for things other than just

memory allocations by the application.

 

A Large Address Aware 32-bit process can get up to 2 GB, 3 GB, or 4 GB of

virtual address space depending on the OS and configuration it is running

on. On 32-bit Windows, such applications can only get 2GB unless the system

has been booted with a special boot option. At most such a special boot

option can give the process up to 3 GB, although this limits the OS to 1 GB

which can cause stability problems. On 64-bit Windows, a Large Address Aware

32-bit application can get up to 4 GB without any special boot options.

 

A 64-bit native process running on a 64-bit OS can address up to 8 TB of

virtual address space in current implementations. Future hardware can extend

support from the current 44 address lines up to 64 over time.

 

I did a presentation for our GameFest event on the issue of VA space and

memory you might find useful:

 

http://download.microsoft.com/download/e/3/c/e3c25fea-2b53-4174-8729-29a4ec16583b/Why%20Your%20Windows%20Game%20Won't%20Run%20In%202,147,352,576%20Bytes.zip

 

There are also specialized 'windowed' extensions you can use to address more

physical RAM from a 32-bit process within the 2 GB virtual address space,

but using them can be tricky.

 

--

Chuck Walbourn

SDE, XNA Developer Connection

 

This posting is provided "AS IS" with no warranties, and confers no rights.

"David F" <dfumento@ATDomaingmail.com> wrote in message

news:unpdFB9GIHA.1164@TK2MSFTNGP02.phx.gbl...

> My understanding is that the maximum program size under Vista 32 is 2 GB

> (is that RAM or RAM and virtual memory?).

>

> 1. What is maximum *physical addressable RAM* for a single 32-bit

> processes?

> 2. What is maximum *virtual address space* for a single 32-bit processes?

> 3. What is maximum *physical adressable RAM* for a single 64-bit process

> in Vista Business 64?

> 4. What is the maximum virtual address space for a single 64-bit process

> in Vista Business 64?

> TIA.

[Guest Mark]

Re: Maxium Program Size in 64-bit Vista?

 

Excellent write-up! Thanks!

 

 

 

"Chuck Walbourn [MSFT]" <chuckw@online.microsoft.com> wrote in message

news:u36MNJ$GIHA.5980@TK2MSFTNGP04.phx.gbl...

> Because Windows is a virtual memory OS, the process limit is based on

> virtual address space, not physical RAM. The physical RAM limits are tied

to

> the OS itself.

>

> 32-bit versions of Windows XP and Vista are limited to 4 GB of physical

RAM,

> although most motherboards & BIOSes don't really expose the full 4 GB. The

> best I've seen is 3.25 GB physical RAM visible with 4 GB installed. 64-bit

> versions of Windows XP and Vista support more, and it depends on the exact

> SKU as to how much, but ranges from 4 GB to 128 GB or more.

>

> A standard 32-bit process can address up to 2 GB of virtual address space.

> Typically this means at most 2 GB of physical RAM, although a fair bit

less

> due the fact that virtual address space is used for things other than just

> memory allocations by the application.

>

> A Large Address Aware 32-bit process can get up to 2 GB, 3 GB, or 4 GB of

> virtual address space depending on the OS and configuration it is running

> on. On 32-bit Windows, such applications can only get 2GB unless the

system

> has been booted with a special boot option. At most such a special boot

> option can give the process up to 3 GB, although this limits the OS to 1

GB

> which can cause stability problems. On 64-bit Windows, a Large Address

Aware

> 32-bit application can get up to 4 GB without any special boot options.

>

> A 64-bit native process running on a 64-bit OS can address up to 8 TB of

> virtual address space in current implementations. Future hardware can

extend

> support from the current 44 address lines up to 64 over time.

>

> I did a presentation for our GameFest event on the issue of VA space and

> memory you might find useful:

>

>

http://download.microsoft.com/download/e/3/c/e3c25fea-2b53-4174-8729-29a4ec16583b/Why%20Your%20Windows%20Game%20Won't%20Run%20In%202,147,352,576%20Bytes

..zip

>

> There are also specialized 'windowed' extensions you can use to address

more

> physical RAM from a 32-bit process within the 2 GB virtual address space,

> but using them can be tricky.

>

> --

> Chuck Walbourn

> SDE, XNA Developer Connection

>

> This posting is provided "AS IS" with no warranties, and confers no

rights.

> "David F" <dfumento@ATDomaingmail.com> wrote in message

> news:unpdFB9GIHA.1164@TK2MSFTNGP02.phx.gbl...

> > My understanding is that the maximum program size under Vista 32 is 2 GB

> > (is that RAM or RAM and virtual memory?).

> >

> > 1. What is maximum *physical addressable RAM* for a single 32-bit

> > processes?

> > 2. What is maximum *virtual address space* for a single 32-bit

processes?

> > 3. What is maximum *physical adressable RAM* for a single 64-bit

process

> > in Vista Business 64?

> > 4. What is the maximum virtual address space for a single 64-bit

process

> > in Vista Business 64?

> > TIA.

>

>

[Guest XS11E]

Re: Maxium Program Size in 64-bit Vista?

 

"Chuck Walbourn [MSFT]" <chuckw@online.microsoft.com> wrote:

> 32-bit versions of Windows XP and Vista are limited to 4 GB of

> physical RAM, although most motherboards & BIOSes don't really

> expose the full 4 GB. The best I've seen is 3.25 GB physical RAM

> visible with 4 GB installed.

 

I show 3.5 GB with Vista 32 and, of course, 4 GB with Vista 64.

 

MB is ASUS A8M2N-LA (HP proprietary), BIOS is the usual HP totally

worthless Phoenix BIOS.

 

 

--

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