Windows uses 4 GB? Really?

August 16, 2008

I’ve done a lot of research regarding this issue and frankly I’m getting a

migraine in the heat of the Southern Oregon 110 degree days! So I quit!!! I

bought 4 GB of RAM because I thought it would speed up my system a bit. My

motherboard happily stated in its manual that it supports 4 GB of RAM. This

crazy issue regarding more than 2 GB of RAM wasn’t readily available I had no

idea about it. So… I happily bought 4 GB of RAM and was proud of it! My

system seemed to boot a bit faster. Microsoft Office seemed to load a bit

faster. Games seemed to run even just a tad faster. I was happy though not

ecstatic. But I was shocked when I noticed that My Computer/Properties showed

only 3.00 GB! Where did my extra 1 GB of RAM go? I added 2 SLI eVGA 8600 GTS

512 DDR3 MB cards and the My Computer/Properties showed only 2.75 GB. Now I

was concerned. My system still seems to run faster than it did with 1 GB. But

I still wanted to know where my extra 1.25 GB of RAM went.

My system:

ASUS A8N-SLI Deluxe with nForce 4 SLI chipset.

AMD Athlon 64-FX 60

750 watt Silverstone power.

4 GB RAM DDR Corsair XMS

WD 200GB 7200 RPM HD

Sound Blaster Audigy 2ZS Platinum

Is my chipset a 64 bit chipset? Or 32 bit?

What I found was that I am now more confused than before. Some info that is

posted here as reference seems to suggest that it is a Windows issue, but

others seem to suggest that it is also a hardware issue. Some seem to suggest

that in order to fully recognize 4 GB of RAM or more you need not only a 64

bit operating system but also a 64 bit computer hardware system. Not just a

64 bit CPU! I am confused!

I would like to know why when I added SLI video cards my usable RAM dropped

by 250 MB! It seems that the information appears to state that the more ram a

video card has the more “addressing” space it needs. Why! And why then does

this whole “addressing” issue with the upper 4th GB of RAM not become an

issue with 2 GB of RAM? This just doesn’t seem logical! Why would you

actually end up losing usable RAM with more than 2 GB of RAM? I’m confused!

So what if I did have 2 GB of RAM? Would my system slow down slightly? What

is this “addressing” issue and why doesn’t it occur at below 2 GB RAM?

Some people seem to think that it is rare for anyone to need more than 512

MB or 1 GB of RAM! WHAT? Who could anyone think this at this time in the

evolution of computers? Anyone who thinks the average computer user doesn’t

need more than 1 GB RAM ought to have their head examined. Most average home

computer users who have a 64 bit CPU are probably using a few if not many

games that require at least 1 GB of RAM! Hell! I don’t even think most people

could tolerate running Windows XP on 512 MB of RAM even though it will run!

Already some games are requiring 2 GB of RAM to run minimum!

The most significant piece of information I have found that was posted in

the 4 Gigs RAM thread by Tim Slattery:

http://h20331.www2.hp.com/Hpsub/downloads/RAM_Allocation_w-WinXP_HP_MWP_x64.pdf Thanks!

Regardless… I have a migraine, It’s too hot, and I still have not got the

answer that is really important to me:

Is my 1.25 GB of RAM that Windows does not report being used at all in any

amount? Am I benefiting at all in any way from my extra 1.25 GB of RAM? Would

my system be any less effective with only 3 GB as everyone seems to convey

that 3 GB is all that is necessary?

That’s all I really want to know? Did I waste my money?

Thanks, stay cool! Buy from http://www.falcon-nw.com

August 16, 2008

Re: Windows uses 4 GB? Really?

Canyon wrote:

> I’ve done a lot of research regarding this issue and frankly I’m getting a

> migraine in the heat of the Southern Oregon 110 degree days! So I quit!!! I

> bought 4 GB of RAM because I thought it would speed up my system a bit. My

> motherboard happily stated in its manual that it supports 4 GB of RAM. This

> crazy issue regarding more than 2 GB of RAM wasn’t readily available I had no

> idea about it. So… I happily bought 4 GB of RAM and was proud of it! My

> system seemed to boot a bit faster. Microsoft Office seemed to load a bit

> faster. Games seemed to run even just a tad faster. I was happy though not

> ecstatic. But I was shocked when I noticed that My Computer/Properties showed

> only 3.00 GB! Where did my extra 1 GB of RAM go? I added 2 SLI eVGA 8600 GTS

> 512 DDR3 MB cards and the My Computer/Properties showed only 2.75 GB. Now I

> was concerned. My system still seems to run faster than it did with 1 GB. But

> I still wanted to know where my extra 1.25 GB of RAM went.

>

> My system:

> ASUS A8N-SLI Deluxe with nForce 4 SLI chipset.

> AMD Athlon 64-FX 60

> 750 watt Silverstone power.

> 4 GB RAM DDR Corsair XMS

> WD 200GB 7200 RPM HD

> Sound Blaster Audigy 2ZS Platinum

>

> Is my chipset a 64 bit chipset? Or 32 bit?

>

> What I found was that I am now more confused than before. Some info that is

> posted here as reference seems to suggest that it is a Windows issue, but

> others seem to suggest that it is also a hardware issue. Some seem to suggest

> that in order to fully recognize 4 GB of RAM or more you need not only a 64

> bit operating system but also a 64 bit computer hardware system. Not just a

> 64 bit CPU! I am confused!

>

> I would like to know why when I added SLI video cards my usable RAM dropped

> by 250 MB! It seems that the information appears to state that the more ram a

> video card has the more “addressing” space it needs. Why! And why then does

> this whole “addressing” issue with the upper 4th GB of RAM not become an

> issue with 2 GB of RAM? This just doesn’t seem logical! Why would you

> actually end up losing usable RAM with more than 2 GB of RAM? I’m confused!

> So what if I did have 2 GB of RAM? Would my system slow down slightly? What

> is this “addressing” issue and why doesn’t it occur at below 2 GB RAM?

>

> Some people seem to think that it is rare for anyone to need more than 512

> MB or 1 GB of RAM! WHAT? Who could anyone think this at this time in the

> evolution of computers? Anyone who thinks the average computer user doesn’t

> need more than 1 GB RAM ought to have their head examined. Most average home

> computer users who have a 64 bit CPU are probably using a few if not many

> games that require at least 1 GB of RAM! Hell! I don’t even think most people

> could tolerate running Windows XP on 512 MB of RAM even though it will run!

> Already some games are requiring 2 GB of RAM to run minimum!

>

> The most significant piece of information I have found that was posted in

> the 4 Gigs RAM thread by Tim Slattery:

> http://h20331.www2.hp.com/Hpsub/downloads/RAM_Allocation_w-WinXP_HP_MWP_x64.pdf Thanks!

>

> Regardless… I have a migraine, It’s too hot, and I still have not got the

> answer that is really important to me:

>

> Is my 1.25 GB of RAM that Windows does not report being used at all in any

> amount? Am I benefiting at all in any way from my extra 1.25 GB of RAM? Would

> my system be any less effective with only 3 GB as everyone seems to convey

> that 3 GB is all that is necessary?

>

> That’s all I really want to know? Did I waste my money?

>

> Thanks, stay cool! Buy from http://www.falcon-nw.com

http://en.allexperts.com/q/PC-hardware-CPU-1023/Windows-XP-memory-limit.htm

Question:

"I have install total 4GB memory on my motherboard. However, it can only

recognize around 3.1GB or less. My friend's SLI board even less than

3GB. What's up? How should I do to recognize 4GB totally?

Answer:

If you installed total 4GB memory, the system will detect less than 4GB

of total memory because of address space allocation for other critical

functions, such as:

- System BIOS (including motherboard, add-on cards, etc..)

- Motherboards resources

- Memory mapped I/O

- configuration for AGP/PCI-Ex/PCI

- Other memory allocations for PCI devices

Different onboard devices and different add-on cards (devices) will

result of different total memory size.

e.g. more PCI cards installed will require more memory resources,

resulting of less memory free for other uses.

On a SLI system, since PCI-Ex graphic cards will occupy around 256MB,

another 256MB will be occupied after you install a 2nd PCI-Ex graphic

card. Hence, 2.75GB memory left only if two SLI cards installed on

A8N-SLI Premium while 3.0GB memory left with one graphic card without

other add-on devices.

This limitation applies to most chipsets & Windows XP 32-bit version

operating system.

If you install Windows XP 32-bit version operating system, we recommend

that you install less than 3GB of total memory. If more than 3GB memory

is required for your system, then below two conditions must be met:

1. The memory controller which supports memory swap functionality is

used. The latest chipsets like Intel 975X, 955X, Nvidia NF4 SLI Intel

Edition, Nvidia NF4 SLI X16, and AMD K8 CPU architecture can support the

memory swap function.

2. Windows XP Pro X64 Ed. (64-bit) or other OS which can address more

than 4GB memory."

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

"The reduction in available system memory depends on the devices that

are installed in the computer. However, to avoid potential driver

compatibility issues, the 32-bit versions of Windows Vista limit the

total available memory to 3.12 GB. See the "More information" section

for information about potential driver compatibility issues.

If a computer has many installed devices, the available memory may be

reduced to 3 GB or less. However, the maximum memory available in 32-bit

versions of Windows Vista is typically 3.12 GB.

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:

• Intel 975X

• Intel P965

• Intel 955X on Socket 775

• 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. The memory

remapping feature allows for the segment of system memory that was

previously overwritten by the Peripheral Component Interconnect (PCI)

configuration space to be remapped above the 4 GB address line. This

feature must be enabled in the BIOS configuration utility on the

computer. View your computer product documentation for instructions that

explain how to enable this feature. Many consumer-oriented computers may

not support the memory remapping feature. No standard terminology is

used in documentation or in BIOS configuration utilities for this

feature. Therefore, you may have to read the descriptions of the various

BIOS configuration settings that are available to determine whether any

of the settings enable the memory remapping feature.

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

http://www.gigabyte.com.tw/Products/Motherboard/Products_Spec.aspx?ProductID=2758

"Memory

1. 4 x 1.8V DDR2 DIMM sockets supporting up to 16 GB of system

memory (Note 1)

2. Dual channel memory architecture

3. Support for DDR2 1066 (Note 2)/800/667 MHz memory modules

Note 1) Due to Windows XP 32-bit operating system limitation, when more

than 4 GB of physical memory is installed, the actual memory size

displayed will be less than 4 GB."

SH: I felt the memory video was the most exciting of the six videos.

http://technet.microsoft.com/en-us/sysinternals/bb469930.aspx

"Sysinternals Video Library

The Sysinternals Video Library is a set of six DVDs that cover essential

Windows troubleshooting topics. Each video is personally presented by

Mark Russinovich and David Solomon. The complete set is available for

order at a discounted price and the first video, Tour of the

Sysinternals Tools, is _free for download_.

http://www.solsem.com/Video/TourofSysinternalsTools.wmv "

The episode on tracking down memory leaks is especially thrilling!

http://technet.microsoft.com/en-us/sysinternals/0e18b180-9b7a-4c49-8120-c47c5a693683.aspx

http://www.solsem.com/videolibrary.html#memory

"Troubleshooting Memory Problems

Discover the real meaning behind the key memory performance counters to

understand process and system memory usage, solve user and kernel memory

leaks, and properly size your paging file.

Click _here_ to view a free four minute sample.

This 120 minute (2 hour) video is divided into the following modules:

1. Overview of Memory Management

2. Process Memory Usage

3. Paging Lists

4. Paging Files

5. Memory Leaks "

SH: Nonetheless, there is hope if you have Windows XP Pro 32-bit.

http://www.microsoft.com/whdc/system/platform/server/PAE/PAEmem.mspx

"Operating systems based on Microsoft Windows NT technologies have

always provided applications with a flat 32-bit virtual address space

that describes 4 gigabytes (GB) of virtual memory. The address space is

usually split so that 2 GB of address space is directly accessible to

the application and the other 2 GB is only accessible to the Windows

executive software.

The 32-bit versions of the Windows 2000 Advanced Server and Windows NT

Server 4.0, Enterprise Edition, operating systems were the first

versions of Windows to provide applications with a 3-GB flat virtual

address space, with the kernel and executive components using only 1 GB.

In response to customer requests, Microsoft has expanded the

availability of this support to the 32-bit version of Windows XP

Professional and all 32-bit versions of Windows Server 2003. ...

The virtual address space of processes and applications is still limited

to 2 GB unless the /3GB switch is used in the Boot.ini file. When the

physical RAM in the system exceeds 16 GB and the /3GB switch is used,

the operating system will ignore the additional RAM until the /3GB

switch is removed. This is because of the increased size of the kernel

required to support more Page Table Entries. The assumption is made that

the administrator would rather not lose the /3GB functionality silently

and automatically; therefore, this requires the administrator to

explicitly change this setting.

The /3GB switch allocates 3 GB of virtual address space to an

application that uses IMAGE_FILE_LARGE_ADDRESS_AWARE in the process

header. This switch allows applications to address 1 GB of additional

virtual address space above 2 GB.

The virtual address space of processes and applications is still limited

to 2 GB, unless the /3GB switch is used in the Boot.ini file. The

following example shows how to add the /3GB parameter in the Boot.ini

file to enable application memory tuning:

[boot loader]

timeout=30

default=multi(0)disk(0)rdisk(0)partition(2)\WINNT

[operating systems]

multi(0)disk(0)rdisk(0)partition(2)\WINNT="????" /3GB

SH: I think shifting the extra 1GB of memory to applications

will in some situations result in fewer disk writes and

retrieval from data stored on the disk which is more efficient.

So there is a software 64-bit OS and a x64 hardware requirement.

More drivers, the problem, are becoming available for 64-bit.

There is an issue about optimizing their performance.

4 gigs of memory should show up in the Bios, check it.

Also the Bios will often have an option which shows how much

Ram memory is diverted to the video card and so possibly changed.

You didn't mention your version Operating System, so since you

have a nice system, I took a chance and provided the boot.ini

switch information in case you have Windows XP Pro.

With Windows, Home is not where the heart is,

Stephen

August 16, 2008

Re: Windows uses 4 GB? Really?

"Canyon" <Canyon@discussions.microsoft.com> wrote in message

news:4D364976-488C-4E39-930C-407F467E3939@microsoft.com...

> I've done a lot of research regarding this issue and frankly I'm getting a

> migraine in the heat of the Southern Oregon 110 degree days! So I quit!!!

> I

> bought 4 GB of RAM because I thought it would speed up my system a bit. My

> motherboard happily stated in its manual that it supports 4 GB of RAM.

> This

> crazy issue regarding more than 2 GB of RAM wasn't readily available I had

> no

> idea about it. So. I happily bought 4 GB of RAM and was proud of it! My

> system seemed to boot a bit faster. Microsoft Office seemed to load a bit

> faster. Games seemed to run even just a tad faster. I was happy though not

> ecstatic. But I was shocked when I noticed that My Computer/Properties

> showed

> only 3.00 GB! Where did my extra 1 GB of RAM go? I added 2 SLI eVGA 8600

> GTS

> 512 DDR3 MB cards and the My Computer/Properties showed only 2.75 GB. Now

> I

> was concerned. My system still seems to run faster than it did with 1 GB.

> But

> I still wanted to know where my extra 1.25 GB of RAM went.

>

> My system:

> ASUS A8N-SLI Deluxe with nForce 4 SLI chipset.

> AMD Athlon 64-FX 60

> 750 watt Silverstone power.

> 4 GB RAM DDR Corsair XMS

> WD 200GB 7200 RPM HD

> Sound Blaster Audigy 2ZS Platinum

>

> Is my chipset a 64 bit chipset? Or 32 bit?

>

> What I found was that I am now more confused than before. Some info that

> is

> posted here as reference seems to suggest that it is a Windows issue, but

> others seem to suggest that it is also a hardware issue. Some seem to

> suggest

> that in order to fully recognize 4 GB of RAM or more you need not only a

> 64

> bit operating system but also a 64 bit computer hardware system. Not just

> a

> 64 bit CPU! I am confused!

>

> I would like to know why when I added SLI video cards my usable RAM

> dropped

> by 250 MB! It seems that the information appears to state that the more

> ram a

> video card has the more "addressing" space it needs. Why! And why then

> does

> this whole "addressing" issue with the upper 4th GB of RAM not become an

> issue with 2 GB of RAM? This just doesn't seem logical! Why would you

> actually end up losing usable RAM with more than 2 GB of RAM? I'm

> confused!

> So what if I did have 2 GB of RAM? Would my system slow down slightly?

> What

> is this "addressing" issue and why doesn't it occur at below 2 GB RAM?

>

> Some people seem to think that it is rare for anyone to need more than 512

> MB or 1 GB of RAM! WHAT? Who could anyone think this at this time in the

> evolution of computers? Anyone who thinks the average computer user doesn't

> need more than 1 GB RAM ought to have their head examined. Most average

> home

> computer users who have a 64 bit CPU are probably using a few if not many

> games that require at least 1 GB of RAM! Hell! I don't even think most

> people

> could tolerate running Windows XP on 512 MB of RAM even though it will

> run!

> Already some games are requiring 2 GB of RAM to run minimum!

>

> The most significant piece of information I have found that was posted in

> the 4 Gigs RAM thread by Tim Slattery:

> http://h20331.www2.hp.com/Hpsub/downloads/RAM_Allocation_w-WinXP_HP_MWP_x64.pdf

> Thanks!

>

> Regardless. I have a migraine, It's too hot, and I still have not got the

> answer that is really important to me:

>

> Is my 1.25 GB of RAM that Windows does not report being used at all in any

> amount? Am I benefiting at all in any way from my extra 1.25 GB of RAM?

> Would

> my system be any less effective with only 3 GB as everyone seems to convey

> that 3 GB is all that is necessary?

>

> That's all I really want to know? Did I waste my money?

>

> Thanks, stay cool! Buy from http://www.falcon-nw.com

Many people believe that adding memory will speed up a PC.

This is not necessarily true. Having more memory helps when

running several concurrent memory-hungry applications, because

it reduces the need to swap out data into the paging file (which is

slow because it is disk-based). When you run a single application

then there is little or no swapping, hence no improvement in speed

even if you add more memory. On the other hand, having lots and

lots of RAM may give you warm feeling deep inside.

August 16, 2008

Re: Windows uses 4 GB? Really?

Canyon wrote:

> I've done a lot of research regarding this issue and frankly I'm

> getting a

> migraine in the heat of the Southern Oregon 110 degree days! So I

> quit!!! I

> bought 4 GB of RAM because I thought it would speed up my system a

> bit. My

> motherboard happily stated in its manual that it supports 4 GB of

> RAM. This

> crazy issue regarding more than 2 GB of RAM wasn't readily available

> I had no

> idea about it. So. I happily bought 4 GB of RAM and was proud of it!

> My

> system seemed to boot a bit faster. Microsoft Office seemed to load a

> bit

> faster. Games seemed to run even just a tad faster. I was happy

> though not

> ecstatic. But I was shocked when I noticed that My

> Computer/Properties showed

> only 3.00 GB!

The place to which odd memory goes

I bet is heaven where angels glow,

And numbers planted, thrive and grow, prosper, bloom, and more

But as for contentment, well,

I fear it goes straight to hell

And that's the tale I have to tell,

Your choice: Abort, retry, ignore.

August 16, 2008

Re: Windows uses 4 GB? Really?

Let's see if I can explain this in a few short paragraphs.

The processor works with data, it brings in data, processes it and

returns data. Every bit of data comes in to the processor from a memory

address and every bit leaving the processor goes to a memory address. A

32-bit processor has 4,294,967,296 memory addresses. This is the

processor's addressable memory range or the Address Space, with these

memory addresses the processor can directly access four gigabytes of

memory.

So what's the problem? The processor has enough addresses for 4GB of

RAM, why isn't it using all of it? The problem is that if the processor

gave all the addresses to the RAM it would have none left for other

things, anything and everything that needs to talk to the processor

would have to do it through the RAM or the processor would have to dump

RAM addresses to talk to other devices!

Your computer is not only made up of RAM, the processor has to work with

other hardware devices, it has to send and get data to and from some

of those other devices. Remember, the processor gets and returns data

to memory addresses, the 32-bit processor has a 4GB address range.

For example, the BIOS and system board will reserve and use a bit less

than 1 megabyte of address space directly at the processor, when the

processor needs to talk with the BIOS or motherboard it will do so

directly by using their reserved addresses, the addresses reserved by

and given to the system board cannot be used by the RAM. This

(oversimplified) example shows why a 32-bit processor cannot use all of

the RAM when 4GB is installed.

So now you may be thinking that 1 megabyte of memory addresses being

lost to the system board is a far cry from what your Windows

installation is seeing and reporting. Well, you see, most PCI devices

can communicate directly with the processor. These devices also reserve

exclusive memory addresses directly at the processor, if the processor

needs to talk to the video card it will do so at the addresses reserved

by the video card, the addresses where the video card is listening.

Your other PCI devices like sound cards, controller cards and so on also

reserve addresses directly at the processor, the processor can send and

receive data directly to and from these devices.

These devices can reserve a lot of address space, a high end sound card

can reserve 100 megabyte or more of Address Space. A video card with

512MB of on board memory has to have a way of sending the data in that

memory to the processor when needed, if all the memory addresses were

used by RAM the processor would have none left to satisfy the needs of

other devices. That is why addresses are reserved for exclusive use by

the PCI devices, the addresses that are reserved for these devices are

in turn not available for RAM addressing. The amount of memory address

space used by these devices can be as little as a few hundred megabytes

and all the way up to 1GB and more.

It is important to note that the other devices do not use RAM, they

reserve or use addresses at the processor and in turn these addresses

are not available for the RAM, the RAM is in fact deprived of the

addresses and the RAM without address space goes unused. To overcome

this address shortage problem (newer) Intel 32-bit processors make use

of Physical Address Extensions (PAE) which widens the address width to

36-bits and greatly increases the available memory address space. The

use of PAE and 36-bit addressing allows the processor to access 64GB of

RAM, the RAM that was previously unaddressed can now be addressed.

The catch is that the PCI devices keep their addresses in the lower 4GB

address range and the previously unavailable address space for the RAM

is shifted *above* the 4GB arena. The problem is that to access the RAM

above the 4GB arena the operating system has to fully support this PAE

feature, if it doesn't it cannot access the RAM in the space above the

4GB boundary. Raymond Chen has explained this very well here:

http://blogs.msdn.com/oldnewthing/archive/2006/08/14/699521.aspx

Windows 2000 Professional, Windows 2000 Server, Windows XP 32-bits and

Vista 32-bits do not make full use of this /PAE feature, they are unable

to use RAM addressed above the 4GB boundary. You need Windows 2000

Advanced Server or better to be able to fully use this /PAE feature.

The only other way around the problem is to use 64-bit processors and

64-bit operating systems.

To see how much memory addresses are reserved and used by hardware

devices look in the Device Manager and view "Resources by Connection".

Expand the Memory tree and you will see the memory map. On 32-bit

servers or on number crunching workstations where RAM usage is very

demanding hardware selection is important. The server should only have

necessary hardware installed in it, superfluous unused devices should be

removed from the server and the video adapter should not have oodles of

memory, most servers only display text and basic stuff, there is usually

no need to stick a 512MB video adapter in a server, nor is there usually

any need for sound cards.

John