7 system memory, 1 overview, 2 memory configurations – Asus M3A-H/HDMI User Manual
Page 27: System memory -15 1.7.1, Overview -15, Memory configurations -15

ASUS M3A-H/HDMI
1-15
1.7.2
Memory configurations
You may install 512 MB, 1 GB, and 2 GB unbuffered ECC/non-ECC DDR2 DIMMs
into the DIMM sockets.
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:
Channel
Sockets
Channel A
DIMM_A1 and DIMM_A2
Channel B
DIMM_B1 and DIMM_B2
M3A-H/HDMI
®
M3A-H/HDMI 240-pin DDR2 DIMM sockets
Recommended memory configurations
Mode
Sockets
DIMM_A1
DIMM_A2
DIMM_B1
DIMM_B2
Single-Channel
Populated
—
—
—
—
—
Populated
—
Dual-channel (1)
Populated
—
Populated
—
Dual-channel (2)
Populated
Populated
Populated
Populated