NOTICE:
cause the computer not to boot.
NOTE:
DIMM slots 1-4 have white latches for easy identification. DIMM slot 5-8
have black latches.
Addressing Memory With 4-GB or Greater Configurations (32-bit
Operating Systems Only)
This computer supports a maximum of 32 GB of memory when eight 4-GB
DIMMs are installed. Current 32-bit operating systems, such as Microsoft
®
Windows
XP and Windows Vista, can use a maximum of 4 GB of address
space; however, the amount of memory available to the operating system is
less than that installed. Certain components within the computer require
address space in the 4-GB range. Any address space reserved for these
components cannot be used by computer memory.
The following components require memory address space:
•
System ROM
•
APIC(s)
•
Integrated PCI devices, such as network connectors and SCSI controllers
•
PCI cards
•
Graphics card
•
PCI Express cards (if applicable)
At start-up, the BIOS identifies the components that require address space.
The BIOS dynamically calculates the amount of reserved address space
required. The BIOS then subtracts the reserved address space from 4 GB to
determine the amount of usable space.
•
If the total installed computer memory is less than the usable address
space, all installed computer memory is available for use only by the
operating system.
•
If the total installed computer memory is equal to or greater than the
usable address space, a portion of installed memory is not available for use
by the operating system.
174
Adding and Replacing Parts
Do not install non-ECC or unbuffered memory modules. Doing so may
®