Addressing Memory With 4-Gb Configurations - Dell Precision Workstation 370 User's & Service Manual

A matched pair of memory modules in connectors DIMM_1
and DIMM_2 (white securing clips)
B matched pair of memory modules in connectors DIMM_3
and DIMM_4 (black securing clips)
NOTE: Memory purchased from Dell is covered under your computer warranty.
NOTICE: If you remove your original memory modules from the computer during a memory upgrade, keep them
separate from any new modules that you may have, even if you purchased the new modules from Dell. If possible, do
not pair an original memory module with a new memory module. Otherwise, your computer may not start properly.
You should install your original memory modules in pairs either in connectors DIMM1 and DIMM2 or connectors DIMM3
and DIMM4.

Addressing Memory With 4-GB Configurations

Your computer supports a maximum of 4 GB of memory when you use four 1-GB DIMMs. Current operating systems, such as
Microsoft® Windows XP, can only use a maximum of 4 GB of address space; however, the amount of memory available to the
operating system is less than 4 GB. 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, SCSI controllers, and IEEE 1394 controllers
PCI or PCI Express devices/cards
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 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 small portion of installed
memory is available for use by the operating system.