65
Appendix A Technical Summary
System Memory Map
ADRESS RANGE
(DECIMAL)
ADDRESS RANGE (HEX) SIZE DESCRIPTION
1024K – 16777216K 100000-3FFFFFFFF 16382MB EXTENDED MEMORY
960K – 1024K F0000-FFFFFF 64K RUNTIME BIOS
896K – 960K E0000-EFFFF 64K BIOS RESERVED
800K – 896K C8000-DFFFF 96K AVAILABLE TO ADAPTER ROMS
640K – 800K A0000-C7FFF 160K VIDEO MEMORY AND BIOS
639K – 640K 9FC00-9FFFF 1K EXTENDED BIOS DATA
512K – 639K 80000-9FBFF 127K EXTENDED CONVENTIONAL
MEMORY
0K – 512K 00000-7FFFF 512K CONVENTIONAL MEMORY
The Q77AX can address up to 32GB of RAM. Typically the address space that is allocated for PCI
add-in cards, PCI Express configuration space, BIOS, and chipset overhead resides above the top of
RAM. On a system that has 32GB of memory installed, it is not possible to use all of the installed
memory due to system address space being allocated for other system critical functions. These
functions include:
- BIOS/SPI Flash device (64Mb)
- Local APIC (19MB)
- Direct Media Interface (DMI) (40MB)
- Front side interrupts (17MB)
- PCI Express configuration space (256MB)
- PCH base address registers for PCI Express ports (up to 256MB)
- Memory-mapped I/O that is dynamically allocated for PCI Express add-in cards (256MB)
A 32 bit Operating System may not be able to use any physical memory above 4GB.
To Next Page
Loading...