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4G system memory support issue!
Question:
When I plug in four sticks 1G Bytes double side DDR RAM module to my mainboard. It should be show total 4G byes memory size in my Operation System . Why I only can see about 3G Bytes or more less in my Operation System ? How can lets show correct 4G Bytes total memory size ?
Answer:
If you plug in 4G Bytes memory to system , the BIOS should be correct recognize total 4G Bytes memory . But the Operation System total memory will show less than 4G Bytes , This root issue from System Resources require addressing which overlap physical memory below 4G Bytes .
When I plug in four sticks 1G Bytes double side DDR RAM module to my mainboard. It should be show total 4G byes memory size in my Operation System . Why I only can see about 3G Bytes or more less in my Operation System ? How can lets show correct 4G Bytes total memory size ?
Answer:
If you plug in 4G Bytes memory to system , the BIOS should be correct recognize total 4G Bytes memory . But the Operation System total memory will show less than 4G Bytes , This root issue from System Resources require addressing which overlap physical memory below 4G Bytes .
e.g. - System BIOS (include mainboard BIOS , add in card BIOS , etc ..)
- Mainboard Resources (I/O APIC)
- Memory Mapped I/O
- PCI / AGP / PCI Express Configuration Space
- Additional PCI Device Memory
- VGA Memory (Video Aperture Size)
- Other chipset and system device .
- Mainboard Resources (I/O APIC)
- Memory Mapped I/O
- PCI / AGP / PCI Express Configuration Space
- Additional PCI Device Memory
- VGA Memory (Video Aperture Size)
- Other chipset and system device .
The different onboard devices or PCI add-in cards on system , It will show different total memory size in Operation System . Example to JETWAY 939GT4- SLI-G mainboard , When you plug in one PCI-Express graphic card , It will occupy 256Mbytes physical system memory , when you make SLI function , Plug in Another one PCI-Express graphic card , it will occupy another 256M bytes physical system memory , so the Operation System will report to remain less 3.0G Bytes system memory (include BIOS / APIC / I/O APIC / VGA memory / LAN device / Audio device .. occupied system memory) Normally , More PCI device installed it will require more memory resources , This limitation appear different platform and chipsets when you work in Windows XP 32-bit edition Operating System . If you install Windows XP 32-bit edition Operating System , we recommend you install less than 3G Bytes system memory . If your system memory over 3G Bytes , you must fit following two condition :
1. The memory controller support “memory swap” function . e.g. Intel 975X, 955X, Nvidia NF4 SLI Intel Edition, Nvidia NF4 SLI X16 , and AMD K8 CPU platform support “memory swap” function .
2. Windows XP Pro X64 Edition . (64bit edition) or other OS which can address more than 4GB memory. You can refer to Intel web link below information:
http://www.intel.com/support/motherboards/server/sb/cs-016594.htm
1. The memory controller support “memory swap” function . e.g. Intel 975X, 955X, Nvidia NF4 SLI Intel Edition, Nvidia NF4 SLI X16 , and AMD K8 CPU platform support “memory swap” function .
2. Windows XP Pro X64 Edition . (64bit edition) or other OS which can address more than 4GB memory. You can refer to Intel web link below information:
http://www.intel.com/support/motherboards/server/sb/cs-016594.htm