Ecc Memory Initialization; Memory Test; Table 5: Supported Ddr2-400 Dimm Populations - Intel SE7520JR2 Technical Manual

Functional Architecture
MCH
Note: On the Server Board SE7520JR2, when using all dual rank DDR-333 or DDR2-400
DIMMs, a total of four DIMMs can be populated. Configuring more than four dual rank DDR-
333 or DDR2-400 DIMMs will result in the BIOS generating a memory configuration error.
Note: Memory between 4GB and 4GB minus 512MB will not be accessible for use by the
operating system and may be lost to the user, because this area is reserved for BIOS, APIC
configuration space, PCI adapter interface, and virtual video memory space. This means that if
4GB of memory is installed, 3.5GB of this memory is usable. The chipset should allow the
remapping of unused memory above the 4GB address, but this memory may not be accessible to
an operating system that has a 4GB memory limit.
3.3.3

ECC Memory Initialization

ECC memory must be initialized by the BIOS before it can be used. The BIOS must initialize all
memory locations before using them. The BIOS uses the auto-initialize feature of the MCH to
initialize ECC. ECC memory initialization cannot be aborted and may result in a noticeable delay
in the boot process depending on the amount of memory installed in the system.
3.3.4

Memory Test

System memory is classified as base and extended memory. Base memory is memory that is
required for POST. Extended memory is the remaining memory in the system. Extended
memory may be contiguous or may have one or more holes. The BIOS memory test accesses
all memory except for memory holes.
Memory testing consists of separate base and extended memory tests. The base memory test
runs before video is initialized to verify memory required for POST. The BIOS enables video as
early as possible during POST to provide a visual indication that the system is functional. At
some time after video output has been enabled, BIOS executes the extended memory test. The
40
E
E
D/R
E

Table 5: Supported DDR2-400 DIMM Populations

Bank 3 – DIMMs 3A, 3B
S/R
E
E
E
E
E
S/R
C78844-002
Intel® Server Board SE7520JR2
D/R
E
S/R
D/R
Bank 2 – DIMMs 2A, 2B
S/R
S/R
E
D/R
E
S/R
S/R
D/R
D/R
S/R
S/R
Bank 1 – DIMMs 1A, 1B
S/R
S/R
S/R
D/R
D/R
D/R
D/R
Revision 1.0