User Guide

Hardware Installation
2-16
2.4 Configuring the System Memory
Pin1 of
Bank1
Pin1 of
Bank0
This mainboard has four 72 pin SIMM
sockets (Single-in-line Memory Module) that
allow you to install system memory from
minimum 4MB up to maximum 512MB.
The SIMM supported by this mainboard can be identified by 4 kinds of factors:
♦ Size: single side, 1Mx32 (4MB), 4Mx32 (16MB), 16Mx32 (64MB), and
double side, 1Mx32x2 (8MB), 4Mx32x2 (32MB), 16Mx32x2 (128MB).
♦ Speed: 60ns or 70ns access time
♦ Type: FPM (Fast page mode) or EDO (Extended data output)
♦ Parity: without parity (32 bit wide) or with parity (36 bit wide).
Because Pentium II processor has 64 bit bus width, the four SIMM sockets
are arranged in two banks of two sockets each, they are Bank0 and Bank1.
Both SIMMs in each bank must be in the same size and type. It is allowed to
have different speed and type in different bank, for example, 70ns FPM in one
bank and 60ns EDO in another bank, in such case, each bank is
independently optimized for maximum performance. The memory timing
requires at least 70ns fast page mode DRAM chip, but for optimum
performance, 60ns EDO DRAM is recommended.
Warning: The default memory timing setting is 60ns to
obtain the optimal performance. Because of the
specification limitation, 70ns SIMM is recommended to
be used only for CPU external clock 60MHz.
Tip: EDO DRAM is designed to improve the DRAM read
performance. Unlike traditional fast page mode, that tri-
states the memory output data to start the precharge
activity, EDO DRAM holds the memory data valid until
the next memory access cycle, which is similar to pipe-
line effect and reduces one clock state.