Asus P4S133 - Manual (Page 29)

ASUS P4S133 motherboard user guide 17
2.5.3 Memory configurations
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. DIMM modules are longer and have different pin contact on each
side and therefore have a higher pin density. SIMM modules have the
same pin contact on both sides.
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 module 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 ask your retailer the
correct DIMM type before purchasing. This motherboard supports four
clock signals.
P4S133
®
P4S133 168-Pin DIMM Sockets
20 Pins
60 Pins
88 Pins
The DIMMs must be 3.3V Unbuffered for this motherboard. To determine
the DIMM type, check the notches on the DIMMs (see figure below).