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Windows 7: 4gb ram but only 3.25 usable?

05 Dec 2009   #11
Ellwood00

Win 7 X64
 
 

Quote   Quote: Originally Posted by smarteyeball View Post
Quote   Quote: Originally Posted by Ellwood00 View Post
so i now have 4095mb of ram. and the hardware is fine and i took the tv turner card out.
And that is why you have your memory back

1mb is always reserved for hardware in x64
well i did the msconfig after i took the card out, i just tried the card but i still had the mem problem


My System SpecsSystem Spec
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23 Apr 2010   #12
Azimuth

Windows 7 x32
 
 

Hi, I have this same problem and its strange because I had 2 Kingston sticks of 2gb (1gb each) and just installed a corsair 2gb single stick. When I had 2 gb it said i had two and now that i have 4 it says 3.25. My motherboard specs say it can handle 16gb.

Also I never added anything else between ram installing
My System SpecsSystem Spec
23 Apr 2010   #13
electrotune1200

Windows 8 Pro
 
 

Quote   Quote: Originally Posted by Azimuth View Post
Hi, I have this same problem and its strange because I had 2 Kingston sticks of 2gb (1gb each) and just installed a corsair 2gb single stick. When I had 2 gb it said i had two and now that i have 4 it says 3.25. My motherboard specs say it can handle 16gb.

Also I never added anything else between ram installing

You're using a x86 version of Windows 7. Having only 3.25gb of ram available is normal.

If you want to have all 4gb available, Install the x64 version.
My System SpecsSystem Spec
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23 Apr 2010   #14
Rhammstein

HP Win7 Pro x64 | Custom Win7 Pro x64
 
 

Yeah x86 cannot address more than 3.25, also, you cannot upgrade a 32bit OS to a 64bit OS. Sucks, you'll have to make a decision.
My System SpecsSystem Spec
23 Apr 2010   #15
zigzag3143

Win 8 Release candidate 8400
 
 

Doesn't anyone search any more??????
My System SpecsSystem Spec
23 Apr 2010   #16
Scotteq

Windows 7 (x64)
 
 

Quote   Quote: Originally Posted by Azimuth View Post
Hi, I have this same problem and its strange because I had 2 Kingston sticks of 2gb (1gb each) and just installed a corsair 2gb single stick. When I had 2 gb it said i had two and now that i have 4 it says 3.25. My motherboard specs say it can handle 16gb.

Also I never added anything else between ram installing

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.
My System SpecsSystem Spec
10 May 2011   #17
dnlpm

Windows 7 Home Premium 64bit.
 
 

Did you check msconfig?
in boot, advance option, the box of max memory must be desactivated
My System SpecsSystem Spec
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 4gb ram but only 3.25 usable?




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