Windows 7 memory

I am trying to understand how to make windows 7 to read my 4 gig of memory I have installed. It tells me that 4 gig is installed but only using 2 gig. I don't understand why it says that 2.00 GB usable? Can anyone help with this issue?

Thanks so much for any responces....

I believe your operating system is 32-bits which supports up to 3.25 GB of memory. If you want to use all of 4 GB, you will have to do a clean install of 64-bits version of Windows 7 =)

Hello billyc247, welcome to Seven Forums!


If you have integrated graphics some will be dedicated to that.

Hello Billy, and welcome to Seven Forums.

As Ted posted, if you do have an onboard integrated graphics chip, then some of your RAM may be set in the BIOS to be allocated for it. Even if you have added a separate graphics card later.


If not, then double check using the tutorial below to make sure that the Maximum memory box is unchecked. If that still does not help, then check the Maximum memory box and select all available memory (highest number) to see if it will use all memory afterwards.

http://www.sevenforums.com/tutorials/66482-memory-set-maximum-amount-used-windows-7-a.html

Hope this helps,
Shawn

Hey thanks to all of you for the help in this problem. I am running windows 7 32bit with no onboard graphics. I am running SLI on a Evga 790i mother board, with q6600 over clocked to 3.0gz. I tried to do some changing with the msconfig, but that didn't work. I think I will format and reinstall the 64 bit and see if things change then.

I will keep you updated on my process. The reason I didn't install the 64bit before was it said my system was not setup for 64bit. Is there something I need to change in the bois in order to be able to install the 64bit of windows 7??

and again.. Thanks for help in this..

Nice to know there is somewhere to get some good answers to questions...

Billy

Hello again Billy.



What said that your system wasn't set up for 64-bit?

Billy,
Not always, but with an amazing frequency, the problem you are seeing is due to an improperly seated memory chip.

Remove chips, reseat chips, problem gone?

If not, then one possible cause is that one of your memory chips is bad.
Leave you first two gigs in. Boot up. Probably all will be welll.
Remove that two gigs and put in the other two into the slot where you just removed the working memory.

If doesn't work, then you've a bad chip.
If does work, leave that memory there and put the rest back in.

Maybe this time they are correctly seated.

SLI ?

What video cards?

Do they have 1 gig of VRAM each?

Graphics controllers do not need to be "integrated" to use up RAM. Every bit of your one or more video cards needs it's own RAM address space which on 32 bit means taking it away from the 4 gigs you have installed. Moving to 64 bit verion of W7 is the only way to fix it.

billyc247 said:

I am trying to understand how to make windows 7 to read my 4 gig of memory I have installed. It tells me that 4 gig is installed but only using 2 gig. I don't understand why it says that 2.00 GB usable? Can anyone help with this issue?

Thanks so much for any responces....

Click to expand...

OK - Since the system says there are 4 gigs installed, then your RAM is seated properly and you don't have a physical issue.


The crux of the matter is your 32 bit version of Win 7.

In a computer all bytes in the memory system need a unique name. This is called an address. For example, if you have 2 GB of main memory, then there are 2147483648 bytes of RAM in your machine, each of which require an address for the operating system to communicate to it. To give these all an address you need 31 bits to do it. Now, if/when you have 32 bits, you can name 4 GB (2 bytes to the 32nd power = 4GB).

This is why the total addressable space available in a 32 bit OS is 4GB – the OS runs out of addresses and cannot communicate/locate any more bytes of memory because of that.

You may think ”Hey, 4GB of address space… 4GB of RAM… What’s the problem” The problem is that memory isn’t the only thing needing an address. If you install a total of 4GB worth of RAM, the system will detect/use/display 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.

This limitation applies to most chipsets & Windows XP/Vista 32-bit version operating systems. Again, this is a limitation of the Operating System not having enough address space to allocate to the system *and* the RAM. Not allocating address space to devices renders them inoperable. Not allocating addresses to RAM simply results in the unaddressed section not being used in an otherwise fully functional computer. Therefore the OS designers assign RAM last.


If you install a Windows operating system, and if more than 3GB memory is required for your system, then the below conditions must be met:

1. A 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, AMD K8 and newer architectures can support the memory swap function.

2. Installation of Windows XP Pro X64 Ed. (64-bit), Windows Vista 64, or other OS which can provide more than 4GB worth of address space.



Note: Windows Vista 32bit SP1 and newer versions will display the installed amount of RAM, regardless of how much is accessible. This is a display change only.

fseal said:

SLI ?

What video cards?

Do they have 1 gig of VRAM each?

Graphics controllers do not need to be "integrated" to use up RAM. Every bit of your one or more video cards needs it's own RAM address space which on 32 bit means taking it away from the 4 gigs you have installed. Moving to 64 bit verion of W7 is the only way to fix it.

Click to expand...

To add: Typically, the 'aperature' needed for each video card is roughly 256 MB. The entire amount of video ram is not memory mapped.

Typically the entire amout IS mapped, though you may be able to make the viewport smaller, it's typically not done. If you have a 512meg card, you'll be 4gig - 0.5 gig - a little more for other hardware. A 1 gig card means 4-1-a smidge, 2x768 means 4-1.5-a smidge and two 1 gig means 4-2-a smidge. Been that way for a long time.

fseal said:

Typically the entire amout IS mapped, though you may be able to make the viewport smaller, it's typically not done. If you have a 512meg card, you'll be 4gig - 0.5 gig - a little more for other hardware. A 1 gig card means 4-1-a smidge, 2x768 means 4-1.5-a smidge and two 1 gig means 4-2-a smidge. Been that way for a long time.

Click to expand...

Incorrect. Perhaps you are thinking of onboard graphics, which typically use physical RAM because they generally have none themselves.

Gamasutra - Features - Sponsored Feature: RAM, VRAM, and More RAM: 64-Bit Gaming Is Here

The Growth of VRAM
Another factor in the PC memory equation has been growing as well: video memory size. In the early days of Direct3D, the typical video card had 16 or 32 MB of Video RAM (VRAM). High-end video cards now have 512 MB, 640 MB, 768 MB, or more VRAM. When video cards had 16 or 32 MB of Video RAM, this memory was mapped directly into every process that used Direct3D for efficient access by the application and video driver.

As video cards grew larger, this became unsustainable. A 768 MB hole in the 2-GB virtual address space of each process would leave very little space for applications. Similarly, taking 768 MB out of the 4 GB physical address space would be too constraining. This problem is exacerbated in dual GPU configurations (SLI®/Crossfire™).


Therefore, video card manufacturers typically implement a 256 MB physical memory window for the video graphics memory, and modern drivers do not create direct process mappings for the entire VRAM size. Process address space is still consumed for working with the AGP aperture (64 MB, 128 MB, or more typically on modern game systems 256 MB in size). While PCIe uses a dynamic aperture, it too is mapped into each process that uses Direct3D.

Click to expand...

(Page 1 of the same article)
Gamasutra - Features - Sponsored Feature: RAM, VRAM, and More RAM: 64-Bit Gaming Is Here

I am thinking of every one of the 10 or so graphics cards I have owned since windows 2000. Every one has mapped their entire vram space over the lower 4 gig. Every one, every byte.

While your quote may be referring to how things work internally. It does NOT reflect how the memory is reserved as far as the user is concerned.

Every byte of the vram is disabled from use by the (32bit) OS from the 4 gig memory space. It's exact, every time, maybe we should take apoll. Though with W7 64 bit the issue is quickly vanishing...

< shrug > Poll away.

But the fact of the matter is that the aperature required/implemented for MMIO for Graphics is 256MB.

Billyc247 can you post your exact motherboard build/version. if you have trouble finding the info get CPU-Z and there is a tab that can tell you what it is.

CPUID

The reason 64x might not work on your system might be because of the CPU/motherboard capabilities. The mobo has to be set up to use 64x the only way around that barrier is to get a new mobo....

Another thing to try is checking the BIOS to make sure the integrated graphics isnt actually using RAM. It should be under advanced>Integrated Chipset it might be set to auto, but can be set down to 32MB....

Also, you can try taking one of the vid cards out and you should see the amount of RAM increase as the hardware is not being allocated in the RAM. this would prove that the RAM works, its just being allocated away.

Be advised, if it is possible to go the 64x route, a clean install will be needed as you cant migrate from 32x to 64x.

has anyone seen or tried this:

copy and paste below in red into an elevated cmd prompt

BCDEdit /set PAE forceenable --enable to use 4GB RAM


I have not done this so please read more about it and beware

Ok, here is the scoop.

ScottEq, you are right... ONLY if the physical memory does NOT sit on top of the video ram. See here: techPowerUp! :: What is AGP Aperture size?

The agp aperature is used to map video ram into physical ram it's true. and more physical ram is used up per process that uses video ram.

BUT

When physical memory is large enough that it actually overlaps the video ram which IS mapped into physical space all the time (On a 32 bit OS with 4 gig of ram installed), then your main memory under that video ram becomes unusable.

So in the case of 4 meg of ram, the first bit of ram that comes off is the 768 meg x 2 of the OP's video card setup. THEN when he runs a game, more memory may be mapped to ram in the process as needed through the AGP aperature.

So in the case of Physical RAM being small enough (say 2 gig) you were correct, but in this case with 4 gig of ram, it was what you said PLUS what I said as far as "missing ram" goes. Playing a game on a machine setup such as the OPs would actually end up using 768x2 PLUS the AGP aperature (maybe, depends on demands of the game) while running, and 768x2MB of ram all the time even with nothing running.

pacinitaly said:

has anyone seen or tried this:

copy and paste below in red into an elevated cmd prompt

BCDEdit /set PAE forceenable --enable to use 4GB RAM


I have not done this so please read more about it and beware

Click to expand...

Here you go mate.

Physical Address Extension (Windows)

Bare Foot Kid said:

pacinitaly said:

has anyone seen or tried this:

copy and paste below in red into an elevated cmd prompt

BCDEdit /set PAE forceenable --enable to use 4GB RAM


I have not done this so please read more about it and beware

Click to expand...

Here you go mate.

Physical Address Extension (Windows)

Click to expand...

awesome Ted as always