User's Manual (1.2b)
2-12
X9SCM/X9SCM-F/X9SCL/X9SCL-F/X9SCL+-F User’s Manual
The table explains the different types of memory supported that can be accomodated
in each memory slot.
DDR3 Unbuffered ECC (UDIMM) Memory
DIMM Slots per
Channel
DIMMs Populat-
ed per Channel
DIMM Type POR Speeds Ranks per DIMM (any
combination)
2 1 Unbuffered
DDR3
1066, 1333 Single Rank, Dual Rank
2 2 Unbuffered
DDR3
1066, 1333 Single Rank, Dual Rank
Note: Due to memory allocation to system devices, the amount of memory that
remains available for operational use will be reduced when 4 GB of RAM is used.
The reduction in memory availability is disproportional.
For Microsoft Windows users: Microsoft implemented a design change in the Win-
dows XP with Service Pack 2 (SP2) and Windows Vista. This change is specic
to the behavior of Physical Address Extension (PAE) mode which improves driver
compatibility. For more information, please read the following article at Microsoft’s
Knowledge Base website at: http://support.microsoft.com/kb/888137.
Possible System Memory Allocation & Availability
System Device Size Physical Memory
Remaining (-Available)
(4 GB Total System
Memory)
Firmware Hub ash memory (System BIOS) 1 MB 3.99
Local APIC 4 KB 3.99
Area Reserved for the chipset 2 MB 3.99
I/O APIC (4 Kbytes) 4 KB 3.99
PCI Enumeration Area 1 256 MB 3.76
PCI Express (256 MB) 256 MB 3.51
PCI Enumeration Area 2 (if needed) -Aligned on 256-MB
boundary-
512 MB 3.01
VGA Memory 16 MB 2.85
TSEG 1 MB 2.84
Memory available to OS and other applications 2.84