Asus M4A78 - Manual (Page 21)

3. Align the other end of the retention bracket to the retention module base. A clicking
sound denotes that the retention bracket is in place.
Ensure that the fan and heatsink assembly perfectly fits the retention mechanism module
base, otherwise you cannot snap the retention bracket in place.
4. Push down the retention bracket lock on the retention mechanism to secure the
heatsink and fan to the module base.
5. When the fan and heatsink assembly is in place, connect the CPU fan cable to the
connector on the motherboard labeled CPU_FAN.
Do not forget to connect the CPU fan connector! Hardware monitoring errors can occur if
you fail to plug this connector.
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:
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
Chapter 1: Product introduction 1-11