Asus P4PE - Manual (Page 36)

2-10 Chapter 2: Hardware information
2.5 System memory
2.5.1 Overview
The motherboard comes with three Double Data Rate (DDR) Dual Inline
Memory Module (DIMM) sockets. These sockets support up to 2GB
system memory using 184-pin unbuffered non-ECC PC2700/PC2100
(FSB533) or PC2100/PC1600 (FSB400) DDR DIMMs.
The following figure illustrates the location of the DDR DIMM sockets.
Notes on DDR technology
The DDR SDRAM technology evolved from the mainstream PC66, PC100,
PC133 memory known as Single Data Rate (SDR) SDRAM. DDR memory
however, has the ability to perform two data operations in one clock cycle,
thus providing twice the throughput of SDR memory.
A DDR DIMM has the same physical dimensions as an SDR DIMM, but it
has a 184-pin footprint compared to the 168-pin of the SDR DIMM. Also, a
DDR DIMM is single notched while an SDR DIMM is double notched.
Therefore, a DDR DIMM is not backward compatible with SDR, and should
be installed only in a socket specially designed for DDR DIMMs.
P4PE
®
P4PE 184-Pin DDR DIMM Sockets
80 Pins
104 Pins
This motherboard supports different memory frequencies depending on
the CPU FSB (Front Side Bus) and the type of DDR DIMM.
CPU FSB DDR DIMM Type Memory Frequency
533 MHz PC2700 333 MHz
PC2100 266 MHz
400 MHz PC2100 266 MHz
PC1600 200 MHz