System Overview 1-13
Note:
When only a single memory module is installed, DIMM
sizes on that module may vary, but when both memory modules are
installed, the DIMM configuration on the two modules should be
identical to support memory interleaving for performance gains.
Depending on how the memory modules are installed, the memory subsystem can
operate in two different modes: interleaved and single-port.
!
Interleaved mode
(two memory modules installed): The memory modules share a
common address range. One memory module responds to even-numbered cache
lines, while the other responds to odd-numbered cache lines. This configuration
offers the highest performance because it allows the two modules to be used in a
balanced fashion, reducing address conflicts. To operate in interleaved mode,
the
DIMMs must be installed in pairs (one on each module) and in the same locations
on each module
.
!
Single port mode
(one memory module installed): The single memory module
responds to all memory addresses. The DIMMs on this single carrier need not be
installed in pairs and can be installed one DIMM at a time.
DIMM Installation Sequence
A single carrier will support DIMM population in various configurations (empty
sockets included). However, when fewer than 16 DIMMs are installed on a memory
module, the preferred population order is to start from the lowest J number and populate
sequentially to the highest. This recommendation helps maintain optimal signal
integrity and thermal performance.
Note:
Maximum capacity is limited to 16 GB with one memory
module installed. This increases to 32 GB with two modules.
Some OSs and application programs use base memory while others use both
conventional and extended memory. Examples:
!
Base memory: MS-DOS, OS/2, Windows NT, and UNIX
!
Conventional and extended memory: OS/2, Windows NT, and UNIX
MS-DOS does not use extended memory; however, some MS-DOS utility programs
like RAM disks, disk caches, print spoolers, and windowing environments use extended
memory for better performance.
BIOS automatically detects, sizes, and initializes the memory array, depending on the
type, size, and speed of the installed DIMMs, and reports memory size and allocation to
the system via configuration registers.
Note:
DIMM sizes and compatibility:
Use DIMMs that have
been tested for compatibility. Contact your sales representative or
dealer for a list of approved DIMMs.
Summary of Contents for Express5800/180Rb-7
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