1.7System memory

1.7.1Overview

The motherboard comes with four Double Data Rate 2 (DDR2) Dual Inline Memory Modules (DIMM) sockets.

A DDR2 module has the same physical dimensions as a DDR DIMM but has a

240-pin footprint compared to the 184-pin DDR DIMM. DDR2 DIMMs are notched differently to prevent installation on a DDR DIMM socket.

The figure illustrates the location of the DDR2 DIMM sockets:

M3A78-EM

DIMM_B2

DIMM_A2

DIMM_B1

DIMM_A1

112 Pins 128 Pins

M3A78-EM 240-pin DDR2 DIMM Sockets

Channel

Sockets

Channel 1

DIMM_A1 and DIMM_A2

Channel 2

DIMM_B1 and DIMM_B2

1.7.2Memory configurations

You may install 256 MB, 512 MB, 1 GB, and 2 GB unbuffered ECC/non-ECC DDR2 DIMMs into the DIMM sockets.

Recommended memory configurations

Sockets

Mode

DIMM_A1

DIMM_B1

DIMM_A2

DIMM_B2

Single-Channel

–

Populated

–

–

Populated

–

–

–

 

Dual-channel (1)

Populated

Populated

–

–

Dual-channel (2)

Populated

Populated

Populated

Populated

 

 

 

 

 

1-16

Chapter 1: Product introduction