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windows 7 shows only 2gb RAM usable out of 8GB!!

I installed windows 7 x86 (32bit version) using bootcamp. System Property shows 8GB(2.17GB usable) and under resource monitor, it shows about 5GB RAM is "hardware reserved". I have the latest 2011 13 inch Macbook pro. Is there some setting I need to adjust to be able to use 4GB RAM which is the limit of 32 bit Windows 7? Thanks!!

2011 macbook pro, Mac OS X (10.6.7), bootcamp

Posted on Apr 11, 2011 7:31 AM

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Posted on Apr 11, 2011 8:29 AM

You are getting the totally 32bit OS can handle. Most people make the same mistake. 4GB is the total addressable space for the OS.

It works this way if you have a Graphics Card with say 500MB memory and say PCI card using 500MB space etc you have just lost 1GB of addressable space. It all adds up and the RAM your system can use is reduced, since it can only address 4GB total.

The only way you will get to use all that memory is to install a 64bit OS. I don’t think you can still apply a 3GB switch to the boot.ini
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Apr 11, 2011 8:29 AM in response to skyfire001

You are getting the totally 32bit OS can handle. Most people make the same mistake. 4GB is the total addressable space for the OS.

It works this way if you have a Graphics Card with say 500MB memory and say PCI card using 500MB space etc you have just lost 1GB of addressable space. It all adds up and the RAM your system can use is reduced, since it can only address 4GB total.

The only way you will get to use all that memory is to install a 64bit OS. I don’t think you can still apply a 3GB switch to the boot.ini

Apr 11, 2011 8:51 AM in response to Toocool4

Thanks Toocool4. The only GPU is Intel HD 3000 which shares RAM. And that shared part is using the usable 2.17GB. the unusable 5GB+ is not being used at all. No extra PCI cards installed on the laptop. Maybe you were suggesting the integrated sound and usb card are using the RAM addresses?

I have a PC desktop that has total 2GB RAM installed and it has NVIDIA GeForce 7300 ( yes i know it's very old...) that has dedicated video memory and also shares 766MB of RAM. My point here is that Windows 7(32bit) shows 2GB RAM without saying something like "1.2 GB usable". This suggest that the shared memory for video is counted as part of "usable" ram.

Apr 12, 2011 4:41 AM in response to skyfire001

Your old PC would not show 1.2 usable, what I mean is the 32 bit OS has a total addressable space of 4GB, so your 2GB + 766MB adds up to less then 3 GB which means you can get away with it.

If you had say 4GB RAM and then add your graphics card with it’s 766MB RAM that would add up to more than the 32 bit can address, so you would not be able to use all of your 4GB RAM.

Apr 12, 2011 9:15 AM in response to Toocool4

yes it makes perfect sense. still i'm surprised so much address space is taken/reserved. with only intel HD 3000 graphic card. 4GB-2.17GB = 1.83GB taken!!

anyway I had about enough about this so I installed windows 7 x64 and now all is good. I just need to see how win 7 64bit gets along with latest PC games like call of duty 4and mass effect 2.....

Thanks again.

Apr 22, 2012 2:19 PM in response to skyfire001

Hi I have a 2011 MacBook Pro with 32bit windows and it says exactly the same this as skyfire available 4GB(usable 2.17 GB) and I have a 1GB AMD Radeon HD 6750M video card with shared memory, so does that mean that it shares that 2.17GB with windows... and if im running heavy graphics my computer will just run super slow? since 1GB is for graphics card and 1GB for windows?


Lately my computer has been running extremely slow, specially when I run games. Can anyone give me any insight on this?

Mar 13, 2013 2:32 PM in response to skyfire001

I have a mac mini with bootcamp and Window 7 Pro 32bits SP1.

I upgraded my machine to 8GB RAM, W7 see the 8GB but, only 2.28GB are usable.

So, I tried to force PAE using bcdedit but doesn't work. In the MSCONFIG, the 'maximum memory' box is unticked.

Next, I tied to path the kernel using the instructions on this page:


http://www.howorks.com/2011/02/24/how-to-remove-windows-7-32bit-4gb-memory-limit /


And it's worked, now W7 see all memory (8GB RAM) and only 25MB are allocated to Reserved Hardware.


Sandro

Mar 13, 2013 2:51 PM in response to senomoto

I would not use this or any other hack from an unknown source. 32bit Windows can only address 2^32 bits of data. Do the math. You need 64bit Windows to address more than that. Do not use a hack that may even be illegal according to the article.


Get the 64bit Windows and set up your system legally and correctly without using unapproved hacks.

Mar 13, 2013 3:44 PM in response to BobTheFisherman

Well, 2ˆ32 bits = 4Gbits = 512MBytes. 😉


Without the patch, W7 allow me to use only 2280 MB, the rest of memory is allocated to "reserved hardware".


I think MAC EFI BIOS doesn't have a feature like Memory Remmapping with this feature, W7 32 bits can use the rest of memory, up to 3.5GB (W7 32bits limit). Or with PAE support, 36 bits physical address (~64GB, using 4GB pages).


I used this patch, because I only use W7 to test 32 bits apps.


This patch is an alternative, but, like BobTheFisherman said, use at your own risk.

windows 7 shows only 2gb RAM usable out of 8GB!!

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