4GB of Memory

[georgiosd]

Dear list,

I am running Windows Vista 32-bit (the complete edition, I forget the
name) on an Intel-based iMac with 4GB of memory.

When I bought it, the firmware that came with it would only allow up
to 3GB of memory so 3GB would show on windows. However, they have
released new firmware that supports all 4GB.

Now Vista recognizes that I have 4GB but uses only up to 3GB according
to task manager.

What can I do to make vista use the whole space?

Thanks
Georgios

 

[Carey Frisch [MVP]]

The system memory that is reported in the System Information dialog box
in Windows Vista is less than you expect if 4 GB of RAM is installed:
http://support.microsoft.com/kb/929605

Why doesn't my Windows PC recognize the whole 4GB of memory I installed?
http://www.crucial.com/kb/answer.aspx?qid=4251


--
Carey Frisch
Microsoft MVP
Windows Desktop Experience -
Windows Vista Enthusiast

---------------------------------------------------------------

Dear list,

I am running Windows Vista 32-bit (the complete edition, I forget the
name) on an Intel-based iMac with 4GB of memory.

When I bought it, the firmware that came with it would only allow up
to 3GB of memory so 3GB would show on windows. However, they have
released new firmware that supports all 4GB.

Now Vista recognizes that I have 4GB but uses only up to 3GB according
to task manager.

What can I do to make vista use the whole space?

Thanks
Georgios

 

[Ken Blake, MVP]

Dear list,

I am running Windows Vista 32-bit (the complete edition, I forget the
name) on an Intel-based iMac with 4GB of memory.

When I bought it, the firmware that came with it would only allow up
to 3GB of memory so 3GB would show on windows. However, they have
released new firmware that supports all 4GB.

Now Vista recognizes that I have 4GB but uses only up to 3GB according
to task manager.

What can I do to make vista use the whole space?

There's nothing you can do (short of switching to 64-bit Vista, if you
have a 64-bit processor).

All 32-bit versions of Windows (not just Vista) have a 4GB address
space. That's the theoretical upper limit beyond which you can not go.
But you can't use the entire 4GB of address space. Even though you
have a 4GB address space, you can only use *around* 3.1GB of RAM.
That's because some of that space is used by hardware and is not
available to the operating system and applications. The amount you can
use varies, depending on what hardware you have installed, but can
range from as little as 2GB to as much as 3.5GB. It's usually around
3.1GB.

Note that the hardware is using the address *space*, not the actual
RAM itself. The rest of the RAM goes unused because there is no
address space to map it too.

 

[Tim Slattery]

Now Vista recognizes that I have 4GB but uses only up to 3GB according
to task manager.
http://members.cox.net/slatteryt/RAM.html

What can I do to make vista use the whole space?

Nothing. A 32-bit system can't do it. 64-bit Vista can. (Note that
32-bit Vista with SP1 will tell you that you have 4GB installed, but
still won't use all of it.)

 

[Nogginsaked]

Switch to 64 bit Vista and the OS will see 4gbs or more of RAM.
Unfortunately many of your programs will not work, drivers may not exist for
your peripherals or be less functional and even more buggy than their 32 bit
counterparts.

 

[Paul Montgomery]

Switch to 64 bit Vista and the OS will see 4gbs or more of RAM.
Unfortunately many of your programs will not work, drivers may not exist for
your peripherals or be less functional and even more buggy than their 32 bit
counterparts.

Is THAT all!???

No problemo! <g>

 

[Gander]

Tim Slattery skrev:

Nothing. A 32-bit system can't do it. 64-bit Vista can. (Note that
32-bit Vista with SP1 will tell you that you have 4GB installed, but
still won't use all of it.)

Doesn't 32-bit systems have PAE - which allows for much more than 4 GB
to be addressed?

 

[Charlie Tame]

Tim Slattery skrev:


Doesn't 32-bit systems have PAE - which allows for much more than 4 GB
to be addressed?

Usually only implemented in "Server" versions because it has limitations.

 

[georgiosd]

Usually only implemented in "Server" versions because it has limitations.

Thanks for all the replies.

I thought that there is PAE switch for Vista... am I mistaken?

 

[Tim Slattery]

Tim Slattery skrev:


Doesn't 32-bit systems have PAE - which allows for much more than 4 GB
to be addressed?

Some 32-bit hardware supports Intel's PAE (programmed address
extensions) kludge, which extends the address space by 4 bits, to
64GB. MS server systems support PAE, MS client systems (XP and Vista)
don't. Most Linux systems support it.

 

[Tim Slattery]

I thought that there is PAE switch for Vista... am I mistaken?

I'm not sure that it does anything in a Vista system. Look here:
http://msdn.microsoft.com/en-us/library/aa366778.aspx

Scroll down a bit to "Physical Memory Limits: Windows Vista" for a
table giving limits for all versions of Vista. For all 32-bit
versions, it's 4GB (and you could only get that if BIOS and Video RAM
were using no address space at all). Limits in 64-bit Vista range from
8GB to 128GB.

 

[Gander]

Tim Slattery skrev:

I'm not sure that it does anything in a Vista system. Look here:
http://msdn.microsoft.com/en-us/library/aa366778.aspx

Scroll down a bit to "Physical Memory Limits: Windows Vista" for a
table giving limits for all versions of Vista. For all 32-bit
versions, it's 4GB (and you could only get that if BIOS and Video RAM
were using no address space at all). Limits in 64-bit Vista range from
8GB to 128GB.

It might only support 4GB RAM, but I think I've read somewhere that the
address space supported is bigger. For example: 0-3G is RAM, 3-4G is
MMIO, and 4-5G is RAM. That gives 5GB address space, but still only 4GB RAM

 

[Tim Slattery]

Tim Slattery skrev:

It might only support 4GB RAM, but I think I've read somewhere that the
address space supported is bigger. For example: 0-3G is RAM, 3-4G is
MMIO, and 4-5G is RAM. That gives 5GB address space, but still only 4GB RAM

Not to my knowledge, anyway. AFAIK, Vista uses PAE only to enable DEP,
not to increase address space.

 

[Colon Terminus]

Tim Slattery skrev:

It might only support 4GB RAM, but I think I've read somewhere that the
address space supported is bigger. For example: 0-3G is RAM, 3-4G is MMIO,
and 4-5G is RAM. That gives 5GB address space, but still only 4GB RAM

On a 32-bit machine, the hardware doodad that develops memory addresses is
32 bits wide.
That means that hardware can develop memory addresses ranging from 0 to
4,294,967,295.
That larger number (2 to the 32nd minus 1) defines the maximum hardware
addressable memory byte. Period.

 

[Paul Montgomery]

On a 32-bit machine, the hardware doodad that develops memory addresses is
32 bits wide.
That means that hardware can develop memory addresses ranging from 0 to
4,294,967,295.
That larger number (2 to the 32nd minus 1) defines the maximum hardware
addressable memory byte. Period.

Nice job goosing the " Gander" ;-)

 

[dennis]

On a 32-bit machine, the hardware doodad that develops memory addresses
is 32 bits wide.
That means that hardware can develop memory addresses ranging from 0 to
4,294,967,295.
That larger number (2 to the 32nd minus 1) defines the maximum hardware
addressable memory byte. Period.

That is not true in PAE mode.

 

[Tim Slattery]

That is not true in PAE mode.

But neither Vista nor XP support PAE.

 

[dennis]

But neither Vista nor XP support PAE.

Colon Terminus was talking about what was possible in hardware. And with
PAE it is very much possible to use more than 32 bits.

Both XP and Vista supports PAE, they just limit the number of bits to 32.

 

[Charlie Tame]

Some 32-bit hardware supports Intel's PAE (programmed address
extensions) kludge, which extends the address space by 4 bits, to
64GB. MS server systems support PAE, MS client systems (XP and Vista)
don't. Most Linux systems support it.

Thank you, Kludge is the word. No disrespect intended, it works but is
not suitable if running software that is not aware of it. IMHO MS have
acted wisely by not implementing it in their consumer versions, and in
any case with 64 bit hardware now easily and cheaply available there is
little point.

Since the history of Linux is with serious users (again no disrespect
intended) and server operators a level of awareness of limitations is
expected.

If you need a lot of RAM you want 64 bit, any software author should be
aware of the RAM needed for his / her application and should write for
the appropriate platform.

 

[dennis]

Thank you, Kludge is the word. No disrespect intended, it works but is
not suitable if running software that is not aware of it. IMHO MS have
acted wisely by not implementing it in their consumer versions, and in
any case with 64 bit hardware now easily and cheaply available there is
little point.

Kludge? Problems arise because some programmers takes shortcuts, and
don't use the OS like they should, and ignore the possibility that
something could exist above 4G. Normal applications doesn't need to be
aware of anything.