1.7
System memory
1.7.1.
Overview
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 240-pin DDR2 DIMM Sockets
Channel
Channel 1
Channel 2
1.7.2
Memory 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
Mode
Single-Channel
Dual-channel.(1)
Dual-channel.(2)
1-16
R
M3A78-EM
Sockets
DIMM_A1 and DIMM_A2
DIMM_B1 and DIMM_B2
DIMM_A1
–
Populated
Populated
Populated
Sockets
DIMM_B1
DIMM_A2
Populated
–
Populated
Populated
Populated
DIMM_B2
–
–
–
–
–
–
Populated
Chapter 1: Product introduction