Vista 32bit only show 2.8GB out of 4GB ??


Nov 4, 2008
Hi there , I know that Vista 32bit can not fully use all the 4GB , but 2.8 is kinda low compared to what other people are getting around 3.2-3.5gb .

I just bought OCZ Reaper PC2-8500 4GB Dual channel kit , running on Gigabyte EP45-DS3L with ATI 4870X2

I dont know why I am getting 2.8ghz , some ppl say its limited by vista 32bit and onboard video card

does any one know how to tweak it to 3GB+ ??
It is because of the graphics memory you are not getting the expected 3.2~3.5GB as the OS also recognizes that as system memory...
Only easiest and possible way is to upgrade the Vista 32 to Vista 64...
you can actually "obtain" an x64 CD and use it with your licence and activate it normal btw - thank god microsoft allowed that (with the exception to Vista Basic etc)

x64 is a requirement for any serious gamer these days
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.