![](/images/new-backgrounds/1172068/172068371x1.webp)
Memory Map
Table 31 lists the system memory map. When BIOS allocates memory space to PCI devices, it starts just below the APICs and continues downward. Assigning memory space to PCI devices does not decrease the total available memory in the system because this memory is “reclaimed” above 4 GB.
The server does not support memory gaps from 512 KB to 640 KB and from 15 MB to 16 MB. These regions are treated as normal system memory.
Table 31. Memory Map
Address Range
00000000 – 0009FFFF
000A0000 – 000AFFFF
000C0000 – 000D7FFF
000C0000 – 000D7FFF
000D8000 – 000DBFFF
000DC000 – 000DFFFF
000E0000 – 000FFFFF
00100000 – PCI Memory allocated to first PCI device
FEC00000 – FEC0FFFF
FEC10000 – FEC1FFFF
FEC20000 – FECFFFFF
FEE00000 – FEF00000
FF000000 – FFDFFFFF
FFE00000 – FFFFFFFF
100000000 – 1FFFFFFFF
Amount
640K
128K
96K
96K
16K
16K
128K
64K
64K
896K
1MB
14MB
2MB
4GB
Function
Base (conventional) System Memory
ISA Video buffer
Allocated to Run time user binary if enabled/programmed, otherwise can be used for options ROM’s
Allocated to Console Redirection if enabled, otherwise can be used for options ROM’s
System BIOS Shadowed
Typically it can go up to 3GB
Reserved. Unused on this platform
Reclaimed. If main memory exceeds this region
IOAPIC allocated to the PID
Reclaimed. If main memory exceeds this region
Reserved
Reclaimed. If main memory exceeds this region
LOCAL APIC
Reclaimed. If main memory exceeds this region
Unused. Reclaimed. If main memory exceeds this region
Main System BIOS
If memory exists
186 | Technical Reference |