XP And RAM

[JD]

I'm using XP home edition with SP3 and I have 4GB of RAM installed. From
previous posts in this newsgroup I learned that 32-bit operating systems
can only address 4GB of RAM.

I found this:

http://support.microsoft.com/kb/929605

It's talking about Vista but I noticed it says:

"WORKAROUND
For Windows Vista to use all 4 GB of memory on a computer that has 4 GB
of memory installed, the computer must meet the following requirements:

The chipset must support at least 8 GB of address space. Chipsets that
have this capability include the following:

Chipsets that support AMD processors that use socket F, socket 940,
socket 939, or socket AM2. These chipsets include any AMD socket and CPU
combination in which the memory controller resides in the CPU.

The CPU must support the x64 instruction set. The AMD64 CPU and the
Intel EM64T CPU support this instruction set.

The BIOS must support the memory remapping feature

An x64 (64-bit) version of Windows Vista must be used."


Even if my AMD AM2 processor and my BIOS meet the above requirements,
I'm still not going to be able to address more than 4GB of memory since
my XP is a 32-bit OS?

 

[Shenan Stanley]

I'm using XP home edition with SP3 and I have 4GB of RAM installed.
From previous posts in this newsgroup I learned that 32-bit
operating systems can only address 4GB of RAM.

I found this:

http://support.microsoft.com/kb/929605

It's talking about Vista but I noticed it says:

"WORKAROUND
For Windows Vista to use all 4 GB of memory on a computer that has
4 GB of memory installed, the computer must meet the following
requirements:
The chipset must support at least 8 GB of address space. Chipsets
that have this capability include the following:

Chipsets that support AMD processors that use socket F, socket 940,
socket 939, or socket AM2. These chipsets include any AMD socket
and CPU combination in which the memory controller resides in the
CPU.
The CPU must support the x64 instruction set. The AMD64 CPU and the
Intel EM64T CPU support this instruction set.

The BIOS must support the memory remapping feature

An x64 (64-bit) version of Windows Vista must be used."


Even if my AMD AM2 processor and my BIOS meet the above
requirements, I'm still not going to be able to address more than
4GB of memory since my XP is a 32-bit OS?

Your last sentence is correct.

 

[John John (MVP)]

I'm using XP home edition with SP3 and I have 4GB of RAM installed. From
previous posts in this newsgroup I learned that 32-bit operating systems
can only address 4GB of RAM.

I found this:

http://support.microsoft.com/kb/929605

It's talking about Vista but I noticed it says:

"WORKAROUND
For Windows Vista to use all 4 GB of memory on a computer that has 4 GB
of memory installed, the computer must meet the following requirements:

The chipset must support at least 8 GB of address space. Chipsets that
have this capability include the following:

Chipsets that support AMD processors that use socket F, socket 940,
socket 939, or socket AM2. These chipsets include any AMD socket and CPU
combination in which the memory controller resides in the CPU.

The CPU must support the x64 instruction set. The AMD64 CPU and the
Intel EM64T CPU support this instruction set.

The BIOS must support the memory remapping feature

An x64 (64-bit) version of Windows Vista must be used."


Even if my AMD AM2 processor and my BIOS meet the above requirements,
I'm still not going to be able to address more than 4GB of memory since
my XP is a 32-bit OS?

That's correct, you need a 64-bit operating system to address more than
4GB of RAM. Some of the 32-bit Server versions can address more than
4GB with the use of PAE but that is another kettle of fish, Windows XP
32-bit cannot do it.

John

John

 

[Ken Blake, MVP]

I'm using XP home edition with SP3 and I have 4GB of RAM installed. From
previous posts in this newsgroup I learned that 32-bit operating systems
can only address 4GB of RAM.

All 32-bit client versions of Windows (not just Vista/XP) 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.

 

[JD]

Your last sentence is correct.

Thanks.

 

[JD]

That's correct, you need a 64-bit operating system to address more than
4GB of RAM. Some of the 32-bit Server versions can address more than
4GB with the use of PAE but that is another kettle of fish, Windows XP
32-bit cannot do it.

John

John

Thanks.

 

[JD]

All 32-bit client versions of Windows (not just Vista/XP) 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.

It took me a little time but I now understand the address space concept
on a 32-bit OS. That's the main reason I went with 256MB of RAM on the
Video card. On my 4GB XP machine, it shows 3.25GB of RAM.

 

[Ken Blake, MVP]

Ken Blake, MVP wrote:\

It took me a little time but I now understand the address space concept
on a 32-bit OS. That's the main reason I went with 256MB of RAM on the
Video card. On my 4GB XP machine, it shows 3.25GB of RAM.

Glad you now understand. Your 3.25GB is a very typical amount you
would get.

Also note that, unless your RAM needs are unusually very high, even
3.25GB is greatly higher that almost anyone needs for XP, and most
people would see no improvement with 3.25GB over 1GB or so.

 

[JD]

Glad you now understand. Your 3.25GB is a very typical amount you
would get.

Also note that, unless your RAM needs are unusually very high, even
3.25GB is greatly higher that almost anyone needs for XP, and most
people would see no improvement with 3.25GB over 1GB or so.

I use CS3 (Photoshop 10) and it is a memory and processor hog. The extra
RAM, dual core processor and two hard drives has made what appears to be
a big difference. My old XP machine was single core, one hard drive and
only 2GB of RAM. I'm still in the process of setting up the new XP
machine but I'd say Photoshop 10 is faster on the new machine. Each GB
of ram was $25. Why not load it up?

 

[Ken Blake, MVP]

I use CS3 (Photoshop 10) and it is a memory and processor hog. The extra
RAM, dual core processor and two hard drives has made what appears to be
a big difference. My old XP machine was single core, one hard drive and
only 2GB of RAM. I'm still in the process of setting up the new XP
machine but I'd say Photoshop 10 is faster on the new machine. Each GB
of ram was $25. Why not load it up?

With Photoshop, using and needing a lot of RAM is by no means unusual.
It probably helps you a great deal.

 

[JD]

If you want to go above 3.25 (or so) gigs of RAM
and your mobo supports it...I highly suggest you go with XP 64 bit.

A few years back I built a machine specifically to run Photoshop (then PS7,
now CS2)
and found XP 64 to be a great OS (IMHO the best OS out there yet)

I suggest installing XP_64 on another partition and dual boot until you get
everything configured...
as you will still have your XP_32 to use in the mean time

As I'm in the process of installing my other programs and moving my data
files to the new XP machine, I really haven't had much time to play with
CS3 on the new machine.

I have played with it a little and it appears to be much faster so I
don't see a dual boot in my future.

That said, things change. Thanks for the suggestion.