# DDR3 4GB detected as 2.99 GB in Xp SP3



## newhariharan2008 (Apr 7, 2009)

hiiiiiiii guys i have just build up my new system 

Intel Core 2 Quad Q9550
Intel DP45SG Main Board
With 2*2GB DDR3 Ram 
XFX 9600GT 1GB DDR3 Graphics Card
With IBall 600W SMPS


But i Have a Big Prob now in m y Xp SP3 my Ram is showing as 2.99 Gb Insted of 4 Gb Can plz any one tell me the solution 


But in my Bios It is showing as 4Gb Ram


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## newhariharan2008 (Apr 7, 2009)

but in my CPU id it is showing as 4Gb Ram ........


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## erocker (Apr 7, 2009)

The 32bit operating system you are using is not capable of addressing 4gb's of RAM.  You need a 64 bit o/s.


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## kg4icg (Apr 7, 2009)

using 32 bit or 64 bit, in which i'm guessing 32 bit in which you take your system ram and subtract the memory in your video card and guess what, that's all 32 bit windows is going to show you. 32 bit win xppro, vista, and even win 7 only use a max of "and read this carefully" 4 gig of total system memory, which in fact includes the mem on a video card.


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## newhariharan2008 (Apr 7, 2009)

erocker said:


> The 32bit operating system you are using is not capable of addressing 4gb's or RAM.  You need a 64 bit o/s.



so if i use 64 bit version of Windows will it show me My 4Gb Of ram


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## erocker (Apr 7, 2009)

Yes it will.


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## newhariharan2008 (Apr 7, 2009)

erocker said:


> Yes it will.



Thanks a lot mate .... have u tested this one ...... bcoz if u say that this is the solution ..... i will download the Xp 64bit version now


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## Mussels (Apr 7, 2009)

newhariharan2008 said:


> Thanks a lot mate .... have u tested this one ...... bcoz if u say that this is the solution ..... i will download the Xp 64bit version now



we all know it. its a very well known fact.


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## newhariharan2008 (Apr 7, 2009)

Mussels said:


> we all know it. its a very well known fact.



sry mate iam just new to this one ........... any how thanks for the kind info ........


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## ShadowFold (Apr 7, 2009)

Don't get XP x64. Vista64 is much more stable and faster.


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## silkstone (Apr 7, 2009)

They're both good SF, but i'd also go with vista x64. Your system will handle vista very nicely


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## Error 404 (Apr 7, 2009)

newhariharan2008 said:


> so if i use 64 bit version of Windows will it show me My 4Gb Of ram



It wont just show you the 4 GB of RAM, it will use it fully! Although Vista 64 would be much better than XP 64 IMO.


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## DaMulta (Apr 7, 2009)

A description of the 4 GB RAM Tuning feature and the Physical Address Extension parameter
http://support.microsoft.com/kb/291988


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## FordGT90Concept (Apr 7, 2009)

This may convince you...

Running XP x64 here and all 6 GiB are registering:







XP x64 has only BSOD'd once in 4 years and that was when I pushed the memory clocks too far.  No overclocks, good drivers, and it is 100% stable.


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## newhariharan2008 (Apr 7, 2009)

FordGT90Concept said:


> This may convince you...
> 
> Running XP x64 here and all 6 GiB are registering:
> http://img.techpowerup.org/090407/x64542.png
> ...



Thanks a lot ........ hw is I7


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## 95Viper (Apr 7, 2009)

DaMulta said:


> A description of the 4 GB RAM Tuning feature and the Physical Address Extension parameter
> http://support.microsoft.com/kb/291988



Yep, you hit the nail right on the head, dead center.

But, I would go with 64 Vista or at, least 64 bit xp, too.


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## DaMulta (Apr 7, 2009)

*4-Gigabyte Tuning*

To enable 4GT, use the BCDEdit /set command to set the increaseuserva boot entry option to a value between 2048 (2 GB) and 3072 (3 GB).

    Windows Server 2003 and earlier:  To enable 4GT, add the /3GB switch to the Boot.ini file. The /3GB switch is supported on the following systems:

        * Windows Server 2003
        * Windows XP Professional
        * Windows 2000 Datacenter Server
        * Windows 2000 Advanced Server

    The /3GB switch makes a full 3 GB of virtual address space available to applications and reduces the amount available to the system to 1 GB. On Windows Server 2003, the amount of address space available to applications can be adjusted by setting the /USERVA switch in Boot.ini to a value between 2048 and 3072, which increases the amount of address space available to the system. This can help maintain overall system performance when the application requires more than 2 GB but less than 3 GB of address space.http://msdn.microsoft.com/en-us/library/bb613473(VS.85).aspx


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## DaMulta (Apr 7, 2009)

Just download windows 7 or use the free windows downloads that can be found on msdn.com


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## FordGT90Concept (Apr 7, 2009)

newhariharan2008 said:


> Thanks a lot ........ hw is I7


A pretty big improvement coming from an Opteron 180.  I waited for Nehalem knowing it would be a major improvement from Core 2/Phenom.  It has waltzed through everything I've thrown at it (mostly games and programming).  The 920 is on par or better performing than my 2 x Xeon 5310 processors.


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## eidairaman1 (Apr 7, 2009)

Another Trick that Does Speed up Overall Windows is Turning off the Paging file, I would only recommend that if you have more than 4 Gigs of Ram tho (if there is more tweaking to  memory managment core). I did this on my laptop with 2 Gigs and sure enough the OS was as speedy as Win98SE on a Athlon XP, drawback was I ran out of Resources during 7Zip maximum Compression.


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## newhariharan2008 (Apr 7, 2009)

FordGT90Concept said:


> A pretty big improvement coming from an Opteron 180.  I waited for Nehalem knowing it would be a major improvement from Core 2/Phenom.  It has waltzed through everything I've thrown at it (mostly games and programming).  The 920 is on par or better performing than my 2 x Xeon 5310 processors.



hmmm,....nice one ... hw is my system config


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## Bokteelo (Apr 7, 2009)

newhariharan2008 said:


> Thanks a lot mate .... have u tested this one ...... bcoz if u say that this is the solution ..... i will download the Xp 64bit version now



How exactly do you download XP 64bit?


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## 95Viper (Apr 7, 2009)

Maybe, he belongs to technet or something...


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## newhariharan2008 (Apr 7, 2009)

Bokteelo said:


> How exactly do you download XP 64bit?



From the world of torrents


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## grunt_408 (Apr 7, 2009)

Maybee he means how do i drive to the shop and buy it???


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## newhariharan2008 (Apr 7, 2009)

ahahhahahahha no way for shopping


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## Mussels (Apr 7, 2009)

newhariharan2008 said:


> From the world of ????????



for the sake of this thread, lets just assume he gets it from technet.

Any discussions of the other places, this thread gets locked.


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## newhariharan2008 (Apr 7, 2009)

Mussels said:


> for the sake of this thread, lets just assume he gets it from technet.
> 
> Any discussions of the other places, this thread gets locked.



ok ............... sry for the over rulling this forum rules


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## Mussels (Apr 7, 2009)

newhariharan2008 said:


> ok ............... sry for the over rulling this forum rules



No problem... we all know you're a legitimate user of the technet service


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## newhariharan2008 (Apr 7, 2009)

Mussels said:


> No problem... we all know you're a legitimate user of the technet service



thakns mate


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## Hayder_Master (Apr 7, 2009)

all 32 bit windows system right now maximum ram read is 3.3G , the 64 bit windows not only support 4G rams but also more i think can read 32GB ram


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## newhariharan2008 (Apr 15, 2009)

http://msdn.microsoft.com/en-us/library/aa366778.aspx

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


Can any one explain what is these links alll about


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## Mussels (Apr 15, 2009)

newhariharan2008 said:


> http://msdn.microsoft.com/en-us/library/aa366778.aspx
> 
> http://www.microsoft.com/whdc/system/platform/server/PAE/PAEdrv.mspx
> 
> ...



http://forums.techpowerup.com/showthread.php?t=91260

try reading this first. it might make more sense.


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## gstyle99 (Apr 18, 2009)

Microsoft dropped the ball with the 4 GIG limitation in windows 32 bit - nough said.


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## ShadowFold (Apr 18, 2009)

gstyle99 said:


> Microsoft dropped the ball with the 4 GIG limitation in windows 32 bit - nough said.



It has nothing to do with microsoft, they can't magically fix x86's limitations.


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## DaveK (Apr 18, 2009)

Forget Windows they can't seem to fix anything 

Get Windows 7, it's legal* on torrents and it looks nicer 

*Well it was free legally but someone probably thinks it's evil


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## Mussels (Apr 18, 2009)

gstyle99 said:


> Microsoft dropped the ball with the 4 GIG limitation in windows 32 bit - nough said.



And you just dropped a really big ball in the shape of a foot, in your mouth.


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## WhiteLotus (Apr 18, 2009)

Mussels said:


> And you just dropped a really big ball in the shape of a foot, in your mouth.



lolz


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## newtekie1 (Apr 18, 2009)

DaMulta said:


> A description of the 4 GB RAM Tuning feature and the Physical Address Extension parameter
> http://support.microsoft.com/kb/291988



The PAE parameter does not allow Windows XP to address any more memory. Even with PAE on, XP will only address 4GB of RAM for driver compatibility reasons.

And all the /3GB command does it re-arrange how the 4GB is divided allowing for programs to use 3GB of the 4GB, and limitting the system to 1GB of the 4GB.  Instead of an even split of 2GB/2GB.

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

This article explains that XP is still limitted to 4GB of RAM, even with PAE enabled.


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## DRDNA (Apr 18, 2009)

Exactly! ^^^^^^^^^^^^^^


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## someone_else (Apr 20, 2009)

DRDNA said:


> Exactly! ^^^^^^^^^^^^^^


Almost but not exactly 

XP SP2 and onwards restricts the OS to 4GB of physical address space and because our hardware memory mapped devices use some of this space not all the 4GB of ram is available regardless of PAE. XP pre sp2 is not restricted to 4GB of physical address space but is still limited to a maximum of 4GB RAM. This basically means you will have ALL 4GB of RAM available  for use with PAE enabled if you have the supporting hardware. The apparent reason for restricting physical address space was reportedly due to device driver problems when mapping outside the first 4GB of address space. 

Interestingly Vista 32-bit is limited to 4GB of address space and a maximum of 4GB RAM by a couple of registry entries which would make it trivial for MS to allow more than 4GB if they ever decided to. In fact it is possible to make some very minor changes to the kernel which will increase these limits. I have done so myself for testing purposes and have been able to use all my 4GB of RAM and without any driver problems at all, normally I would be limited to 3GB of RAM with 4GB installed. Having said that though, at this time 3GB is more than I ever use so at the moment it's no real issue.


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## newhariharan2008 (Apr 20, 2009)

ok so then y does MS define that PAE


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## gstyle99 (Apr 20, 2009)

Watch out, he is aiming that +10 manta enchanted bow at you.


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## <<Onafets>> (Apr 20, 2009)

So is Win 7 free and legal from T@o@r@r@e@n@t@s?

EDIT: I mean....Technet....Yeah....Technet...


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## someone_else (Apr 21, 2009)

newhariharan2008 said:


> ok so then y does MS define that PAE


Not sure what your trying to ask here, something about PAE.

A good article on PAE http://en.wikipedia.org/wiki/Physical_Address_Extension

PAE or *P*hysical *A*ddress *E*xtension was introduced by Intel on the 32-bit Pentium Pro CPU way back in 1995. If we count the address pins on 32-bit CPUs with PAE we see that there are 36 of them. This means the CPU can address 2^36 or 64GB of physical address space. The CPU in itself is not enough to be able to use 4GB or more of RAM the northbridge chip must also have an interface which is greater than 32-bits. The northbridge is generally responsible for memory, PCI and graphics so if we only have a 32-bit interface, 2^32 = 4GB then our PCI / graphics has to fit into that 4GB leaving less than 4GB of space for our RAM.

So we can address upto a bit less than 64GB of RAM with PAE, a northbridge with 36-bit interface, a computer that supports 64GB of RAM and an OS that allows us to use the full physical address space and is not memory capped.

Note that we must not confuse physical address space with virtual address space, virtual address space on a 32-bit OS is limited to 32-bits or 4GB of which most programs will only be able to use a maximum of just under 2GB of memory as explained in earlier posts. There are exceptions with 4GT which can allow just under 3GB if the program is large address aware. Interestingly a 32-bit program which is large address aware running on a 64-bit OS can use close to 4GB of memory. 

The virtual address space is taken from the physical address space using page tables so although our per process virtual address space is limited to 4GB of which we can generally only use less than 2GB, we are able to run several processes using 1 or 2GB each providing we have the hardware and the OS allows us.

Hope this helps and that I haven't over simplified things too much.


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