In regards to your issue, If you installed total 4GB memory, the system will detect 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. In fact, when you do not install full 4GB memory, memory controller can use free 1GB memory address lines will be used for "PCI memory" to allocate PCI devices.
But, if you install full 4GB memory modules on this MB, memory controller will not have more address line to allocate PCI devices. Thus, BIOS will uses system memory space for PCI device allocation, then you will find shortage of total system memory capacity.
For example, a PCI-E VGA card needs 256MB system memory to allocate, and also needs extra system memory space for onboard audio chip, LAN controller and others. Usually, you will lose around 1GB memory space for that.
This limitation applies to most chipsets & Windows XP 32-bit version operating system.
If you install Windows XP 32-bit version operating system, we recommend that you install less than 3GB of total memory. Windows XP Pro X64 Ed. (64-bit) or other OS which can address more than 4GB memory
We also provide the FAQ on our website: http://www.gigabyte.com.tw/Support/M...spx?FAQID=1493
At last, if you still have any further question or suggestion about our products/service, please do not hesitate to contact with us directly. We will try our best to help you resolve the problem ASAP.
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