Windows 7 x86 Ultimate - 3 GB RAM limits

Hello Experts,

I have a laptop with Win 7 Ultimate x86 and 4 GB RAM.
It shows that it has 4 GB of RAM with 2,96 usable.

I know that Vista SP2 resolved this issue, correcting the *DISPLAY* that it's using 4GB of 4GB.
I know so far that the problem is related to address space. So, the maximum adress space is for 4GB. Some of those addresses are used by integrated video card, s-ata controllers and other devices.
Therefore, an 32 bit OS will be able to use ONLY 3,5 GB of RAM or so.

Now, to be able to use only 2,96 of 4 GB is too much.

Can someone explain the issue in detail?
How can I find out exactly what device uses how many addresses?
Who is Participating?
LMiller7Connect With a Mentor Commented:
The explanation is really quite simple.
A 32 bit client version of Windows is limited to a 4GB physical address space. It would be nice if all of that space could be used for RAM, but unfortunately that is not practical. For performance reasons many hardware devices must be mapped into this address space. It is not that these devices require a great deal of RAM, it is just that they require the address space. Video adapters are a big user but they are by by means the only ones. Many popular video adapters use shared system RAM to cut costs.

The problem is really a hardware issue, not the OS. Typically you will be left with about 2.8 to 3.5GB, depending on the hardware. If the video adapter uses shared memory it may be substantially less.

Vista SP2 made only a cosmetic change to this. The System properties dialog showed installed RAM, not what could actually be used. This kept uninformed users happy but didn't change anything about memory availability.

These technical problems could probably be solved, remembering of course that this is a hardware issue. But considering that 32 bit systems are virtually obsolete the effort would be wasted.

Server operating systems do offer a solution to this problem, with compatible hardware, but this has some serious issues. It is not supported on any current client version of Windows.

If you want to use the full 4GB (or more) RAM you must use a 64 bit OS.
ggefterConnect With a Mentor Commented:

I thought this was a slam-dunk, but it turns out to be a damn good question! The short answer is, the practical upper limit is usually about 3GB of RAM.

The long answer takes some explanation… Here’s the official answer from Microsoft:
ggefter is right, if you want full use of that ram upgrade to ultimate x64 and that is a very good link at MS
Mohammed RahmanCommented:
This might sound different, try re seat RAM and PROCESSOR (important) Also, try to blow some air in the processor socket so that the dust can be removed and all the pins can have proper contact.
Also check this...
Access msconfig
go to boot settings
go to advance settings
under max memory check the amount of RAM it is displaying, and make the corrections.
Also check theamount of memory shared in BIOS.

Please let us know if this worked.
MariusSunchaserAuthor Commented:
Thank you for your comments.
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