DDR 2 Ram Not Read Correct Memory Size with GA-8I945P-G(rev. 1.0)

[matrixlover]

1- Why Ram Not Read Full Memory Size 4 GB even on System Startup or In Windows some Times Read 3 or 3.25 GB On Buss 800.

2- Why Buss 667 Read 3.5 GB installed but usable 3.25 GB .

Does It Related to Processor Buss to read Full Size and will work with full benefit even memory read like this ??!!

And Why It Reserved for system Even There r External VGA i want to understand PLZ Help Me Thxxxxxxxxx

 

[T_T]

For starters, in an x86 environment, 4GB is the maximum addressable amount. 32-bit operating systems support an address range of up to 4 GB for virtual memory addresses and up to 4 GB for physical memory addresses. Because the physical memory addresses are sub-divided to manage both the computer’s PCI memory address range (also known as MMIO) and RAM, the amount of available RAM is always less than 4 GB.

The PCI memory addresses starting down from 4 GB are used for things like the BIOS, IO cards, networking, PCI hubs, bus bridges, PCI-Express, and video/graphics cards. The BIOS takes up about 512 KB starting from the very top address. Then each of the other items mentioned are allocated address ranges below the BIOS range. The largest block of addresses is allocated for today’s high performance graphics cards which need addresses for at least the amount of memory on the graphics card. The net result is that a high performance x86-based computer may allocate 512 MB to more than 1 GB for the PCI memory address range before any RAM (physical user memory) addresses are allocated.

 

[matrixlover]

For starters, in an x86 environment, 4GB is the maximum addressable amount. 32-bit operating systems support an address range of up to 4 GB for virtual memory addresses and up to 4 GB for physical memory addresses. Because the physical memory addresses are sub-divided to manage both the computer’s PCI memory address range (also known as MMIO) and RAM, the amount of available RAM is always less than 4 GB.

The PCI memory addresses starting down from 4 GB are used for things like the BIOS, IO cards, networking, PCI hubs, bus bridges, PCI-Express, and video/graphics cards. The BIOS takes up about 512 KB starting from the very top address. Then each of the other items mentioned are allocated address ranges below the BIOS range. The largest block of addresses is allocated for today’s high performance graphics cards which need addresses for at least the amount of memory on the graphics card. The net result is that a high performance x86-based computer may allocate 512 MB to more than 1 GB for the PCI memory address range before any RAM (physical user memory) addresses are allocated.

If u Mean OS my Windows 7 64 Bit I hope i Get ur Mean