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2
Technical Reference
2.1
Memory Resources
2.1.1
Addressable Memory
The kit utilizes 32 GB of addressable system memory. Typically the address space that is
allocated for PCI Conventional bus add-in cards, PCI Express configuration space, BIOS (SPI Flash
device), and chipset overhead resides above the top of DRAM (total system memory). On a
system that has 32 GB of system 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 the following:
•
BIOS/SPI Flash device (64 Mb)
•
Local APIC (19 MB)
•
Direct Media Interface (40 MB)
•
PCI Express configuration space (256 MB)
•
PCH base address registers PCI Express ports (up to 256 MB)
•
Memory-mapped I/O that is dynamically allocated for M.2 add-in cards (256 MB)
•
Integrated graphics shared memory (up to 512 MB; 64 MB by default)
The kit provides the capability to reclaim the physical memory overlapped by the memory
mapped I/O logical address space. The kit remaps physical memory from the top of usable DRAM
boundary to the 4 GB boundary to an equivalent sized logical address range located just above
the 4 GB boundary. All installed system memory can be used when there is no overlap of system
addresses.
2.2
Connectors and Headers
CAUTION
Only the following connectors and headers have overcurrent protection: back panel and front
panel USB.
The other internal connectors and headers are not overcurrent protected and should connect only
to devices inside the kit’s chassis, such as fans and internal peripherals. Do not use these
connectors or headers to power devices external to the kit’s chassis. A fault in the load presented
by the external devices could cause damage to the board, the power cable, and the external
devices themselves.
Furthermore, improper connection of USB header single wire connectors may eventually overload
the overcurrent protection and cause damage to the board.
