ASUS P3B-1394 User’s Manual 21
3. HARDWARE SETUP
3.5.2 DIMM Installation
Insert the module(s) as shown. Because the number of pins are different on either
side of the breaks, the module will only fit in the orientation shown. DRAM SIMM
modules have the same pin contacts on both sides. SDRAM DIMMs have different
pin contacts on each side and therefore have a higher pin density.
P3B-1394
®
P3B-1394 168-Pin DIMM Memory Sockets
20 Pins
60 Pins
88 Pins
Lock
The DIMMs must be 3.3Volt unbuffered SDRAMs. To determine the DIMM type,
check the notches on the DIMMs (see figure below).
168-Pin DIMM Notch Key Definitions (3.3V)
DRAM Key Position
Voltage Key Position
Unbuffered
RFU
Buffered
Reserved
3.3V
5.0V
The notches on the DIMM will shift between left, center, or right to identify the type
and also to prevent the wrong type from being inserted into the DIMM slot on the
motherboard. You must tell your retailer the correct DIMM type before purchasing.
This motherboard supports four clock signals per DIMM.
System Memory
3. H/W SETUP