Chapter 2: Installation
2-11
duced when 4 GB of RAM is used. The reduction in memory
availability is disproportional. See the following table for details.
For Microsoft Windows users: Microsoft implemented a design
change in the Windows XP with Service Pack 2 (SP2) and Win
-
dows Vista. This change is specific to the behavior of Physical
Address Extension (PAE) mode which improves driver compat-
ibility. 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 flash 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
Memory Population Guidelines
When installing memory modules, the DIMM slots should be populated in the
following order: DIMMA2, DIMMB2, then DIMMA1, DIMMB1.
•
Always use DDR3 DIMM modules of the same size, type and speed.
•
Mixed DIMM speeds can be installed. However, all DIMMs will run at the
speed of the slowest DIMM.
Recommended Population (Balanced)
DIMMA2
DIMMB2
DIMMA1
DIMMB1
Total System Memory
2GB
2GB
4GB
2GB
2GB
2GB
2GB
8GB
4GB
4GB
8GB
4GB
4GB
4GB
4GB
16GB
8GB
8GB
16GB
8GB
8GB
8GB
8GB
32GB
