Why full RAM capacity is not shown?

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techani

Journeyman
I have just installed 4 gb ram with 2x2gb modules. But the system is showing only 2808gb ram! Why is that happening? My system config is
Processor - 6420
M/B ASUS P5B-VM
XP Home with Sp3
 
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Its a windows 32bit bug which microsoft has not been able to effectively fix. 32bit windows recoganises only 4GB memory maximum. So if you have a graphics card, the ram recoganised is even less.

So switch to 64bit windows.
 

infra_red_dude

Wire muncher!
I have just installed 4 gb ram with 2x2gb modules. But the system is showing only 2808gb ram! Why is that happening? My system config is
Processor - 6420
M/B ASUS P5B-VM
XP Home with Sp3
There is definitely some problem with either the settings, ram slots or the RAM chips. 4GB (2x2GB) should at least show about 3.5GB on a 32-bit Windows installation.

Its a windows 32bit bug which microsoft has not been able to effectively fix. 32bit windows recoganises only 4GB memory maximum. So if you have a graphics card, the ram recoganised is even less.

So switch to 64bit windows.
Thats bullsh!t. Its no bug in Windows. 32-bit software/OS can address only 2^32 = 4GB address space. Since even the I/O devices are memory mapped, about 0.5GB of address space is reserved for them. This is the reason why 32-bit OS can see only 4GB - 0.5GB (reserved) ~ 3.5GB RAM. Hafing a graphics card has got nothing to do with the 'ram recognized'.

Tho there are ways to force the OS to see the whole of 4GB (using PAE).
 

Kl@w-24

Slideshow Bob
^ Exactly, the 32-bit limitation.

But maybe his onboard graphics solution is taking up 512 MB of memory and the remaining is being used for addressing the devices attached to the system. Usually when the RAM is shared by the graphics card, Windows deducts the amount and then displays it as the total available RAM. My old 6100 IGP used to share 256 MB of RAM from my 512 MB, so Windows system info (sysdm.cpl) used to only show 256 MB.
 
Thats bullsh!t. Its no bug in Windows. 32-bit software/OS can address only 2^32 = 4GB address space. Since even the I/O devices are memory mapped, about 0.5GB of address space is reserved for them. This is the reason why 32-bit OS can see only 4GB - 0.5GB (reserved) ~ 3.5GB RAM. Hafing a graphics card has got nothing to do with the 'ram recognized'.

Tho there are ways to force the OS to see the whole of 4GB (using PAE).
The thing is buggy because PAE never works as good in windows as other OSes. Thats all I said. ;-)

Its rumored to be intentional because that way more people will shift to 64bit which will be a GOOD thing, since even PAE has a limit of 16GB which can be surpassed pretty soon, considering Nehalem owners already have 12GB RAM and once 4GB sticks become mainstream, they will go for 3x2x4 = 24GB triple channel DDR3 RAM and then complain once again that windows has too little RAM addressing capacity. Anyway, I'm not complaining. I actually WANT MS to give prominance to 64bit by making Windows 7 Ultimate 64bit exclusive. :D

Anyway, the 4GB memory includes:

1. I/O Devices
2. RAM
3. Graphics RAM
4. Onboard RAM in motherboard
5. Something else if I forgot to mention it.

So totally out of 4GB you need to subtract GBs for everything and if you still see a good difference, its an issue with the RAM or the moterboard.
 
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asingh

Aspiring Novelist
But still the Windows program should show ~3.2 GB, with 4 GB installed. If you go to task manager and click on "Help About" you will see how much memory is exactly available to the 32-BIT OS for addressing and utilization. It does not show this number after subtracting memory mapping for GPU/RAM/On board..etc.

You should enable Physical Address Extension and Windows will see ~3.2 GB. But never see 4GB with 32 BIT OS.
 

surinder

Tech addict
I have just installed 4 gb ram with 2x2gb modules. But the system is showing only 2808gb ram! Why is that happening? My system config is
Processor - 6420
M/B ASUS P5B-VM
XP Home with Sp3
What 2808gb of RAM :shock: oh no it is lots of RAM if your 32 bit OS converting your 4 GB RAM to that much then why are you complaining.:D

OK OK if you want to fully utilize your 4 GB of RAM switch to 64 bit version of your OS.
 

infra_red_dude

Wire muncher!
^ Exactly, the 32-bit limitation.

But maybe his onboard graphics solution is taking up 512 MB of memory and the remaining is being used for addressing the devices attached to the system. Usually when the RAM is shared by the graphics card, Windows deducts the amount and then displays it as the total available RAM. My old 6100 IGP used to share 256 MB of RAM from my 512 MB, so Windows system info (sysdm.cpl) used to only show 256 MB.
What he reports is about 2808MB ~ 2.75GB. I find it hard to believe that almost about 1GB of RAM is allocated for onboard graphics. I am yet to see a mobo which allows 1GB allocation. I maybe wrong tho.

The thing is buggy because PAE never works as good in windows as other OSes. Thats all I said. ;-)

Its rumored to be intentional because that way more people will shift to 64bit which will be a GOOD thing, since even PAE has a limit of 16GB which can be surpassed pretty soon, considering Nehalem owners already have 12GB RAM and once 4GB sticks become mainstream, they will go for 3x2x4 = 24GB triple channel DDR3 RAM and then complain once again that windows has too little RAM addressing capacity. Anyway, I'm not complaining. I actually WANT MS to give prominance to 64bit by making Windows 7 Ultimate 64bit exclusive. :D
I've never used PAE myself, never had the need to; so can't comment about its implementation in any OS being buggy.

Btw, PAE enables 36bit addressing, so thats 2^36 ~ 64GB of addressable memory. But many OS' haf addressing limitation of 16-20GB (thats decided purely by the company developing the OS).

Anyway, the 4GB memory includes:

1. I/O Devices
2. RAM
3. Graphics RAM
4. Onboard RAM in motherboard
5. Something else if I forgot to mention it.

So totally out of 4GB you need to subtract GBs for everything and if you still see a good difference, its an issue with the RAM or the moterboard.
Only the first 2 points are correct. Graphics RAM does not share the system address space (and hence is not system addressible); I am yet to see a desktop mobo with on-board ram and there is nothing you forgot to mention. The address space is shared only by the system RAM and the I/O devices. The address space of the latter does not exceed 0.5GB (in most cases).

But still the Windows program should show ~3.2 GB, with 4 GB installed. If you go to task manager and click on "Help About" you will see how much memory is exactly available to the 32-BIT OS for addressing and utilization. It does not show this number after subtracting memory mapping for GPU/RAM/On board..etc.

You should enable Physical Address Extension and Windows will see ~3.2 GB. But never see 4GB with 32 BIT OS.
Yes, that is correct and thats a really well thought of suggestion :)
 

asingh

Aspiring Novelist
By the way..just upgraded to XP-PRO-64BIT last night. OS can now see the full solide 4 GB of ram...! Am Happy..performance..is faster...!
 
What he reports is about 2808MB ~ 2.75GB. I find it hard to believe that almost about 1GB of RAM is allocated for onboard graphics. I am yet to see a mobo which allows 1GB allocation. I maybe wrong tho.

Some of the newer stuff do.


I've never used PAE myself, never had the need to; so can't comment about its implementation in any OS being buggy.
Google around. PAE is possible to be enabled from Command Prompt in Win32. But it has issues.

Only the first 2 points are correct. Graphics RAM does not share the system address space (and hence is not system addressible); I am yet to see a desktop mobo with on-board ram and there is nothing you forgot to mention. The address space is shared only by the system RAM and the I/O devices. The address space of the latter does not exceed 0.5GB (in most cases).
Onboard RAM is found in MOST AMD 790GX boards and in SOME 780G boards.

And Graphics RAM in my statement means memory used by IGP.

Think of it this way - 0.5GB used by I/O devices and 0.5GB by IGP. Makes sense if around 1GB is missing.
By the way..just upgraded to XP-PRO-64BIT last night. OS can now see the full solide 4 GB of ram...! Am Happy..performance..is faster...!
See ? I was right about the issue being of 32bit limitation. :lol:

Anyway, glad that you found an increase in performance after moving to 64bit. Only if everybody with a good system moves to 64bit can Lin64/Win64 become mainstream. :)
 

infra_red_dude

Wire muncher!
By the way..just upgraded to XP-PRO-64BIT last night. OS can now see the full solide 4 GB of ram...! Am Happy..performance..is faster...!
Glad you figured out the problem.

Google around. PAE is possible to be enabled from Command Prompt in Win32. But it has issues.
Maybe, but since I've used PAE myself hence refrained from commenting.

Onboard RAM is found in MOST AMD 790GX boards and in SOME 780G boards.
This is news to me. I never bothered to check that out.

And Graphics RAM in my statement means memory used by IGP.
Yeah, I figured out that your meant the shared memory.

Think of it this way - 0.5GB used by I/O devices and 0.5GB by IGP. Makes sense if around 1GB is missing.
What about the the other 0.25GB? Do the new boards allow upto 1GB to be shared? I'm curious. Been a long long time since I've handled a desktop.
 
This is news to me. I never bothered to check that out.
Its been here since an year. Don't tell me you were out of touch for that long :shock:
I see you online EVERYDAY.

What about the the other 0.25GB? Do the new boards allow upto 1GB to be shared? I'm curious. Been a long long time since I've handled a desktop.
Yeah, the limit is closer to 768MB of shared memory these days for Intel. Some boards allow you to raise it even higher. AMD/nVidia onboard solutions even allow you to use 1GB although heaven knows who will need it.
 

asingh

Aspiring Novelist
lets..start again....Where exactly are you seeing ...that your system is reporting...2808 MB RAM...? Which is ~2.74 GB of RAM...?

Mapping or No mapping of other add - on devices, this is too less. From where on your system are you pulling this number. It does not matter how much stuff you have attached on your system...it should report out correct ram. I have a 1 GB GPU card on my system...and.....

1. XP - 32 BIT : System reported 3.2GB (PAE Enabled)
2. XP - 64 BIT : System reported 4.0GB

..??
 

infra_red_dude

Wire muncher!
Its been here since an year. Don't tell me you were out of touch for that long :shock:
I see you online EVERYDAY.
Yes, dude. I was unaware of the fact that 790xx boards haf onboard RAM. Being online has nothing to do with not knowing about this. I've hardly played around with AMD procs since about an year or so... But i'm pretty sure almost no or just about one or two Intel boards feature this.
 
The bottomline is that he switched to 64bit and the problem seems to be solved.
Let it remain that way. :smile:

I guess he might have had a typo or somehing and stated a higher level of reduction than intended, but lets consider the matter closed.
 

acewin

Point Blanc
I got 1GB and 512 MB RAM sticks, but my system also doesnt not sow correctly all the RAM. I checked in CPU-Z and found the capacity showing in them and found aroun 100 or 64 MB less shown in my computer. which I think is being utilized be my onboard gfx.
 
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