User Guide

Hardware Installation
2-25
Caution: Note that DIMM3 shares a bank with SIMM1 and
SIMM2, so you couldn't use a doulbe side DIMM if SIMMs were
installed.
Caution: There are some old DIMMs made by EDO or FPM
memory chip, they can only accept 5V power and probably can
not fit into the DIMM socket, make sure you have 3.3V true
SDRAM DIMM before your insert it.
There is an important parameter affects SDRAM performance,
CAS Latency
Time
. It is similar as CAS Access Time of EDO DRAM and is calculated as
number of clock state. If your SDRAM has unstable problem, go into BIOS
"Chipset Features Setup", change CAS Latency Time to 3 clocks.
The driving capability of new generation chipset is limited because the lack of
memory buffer (to improve performance). This makes DRAM chip count an
important factor to be taking into consideration when you install DIMM.
Unfortunately, there is no way that BIOS can identified the correct chip count,
you need to calculate the chip count by yourself. The simple rule is: By visual
inspection, use only DIMM which is less than 16 chips.
Warning: Although this motherboard supports x4 SDRAM chip.
Due to loading issue, it is not recommended to use this kind of
SDRAM.
Tip: The DIMM chip count can be calculated by following
example:
1. For 32 bit non-parity SIMM using 1M by 4 bit DRAM chip,
32/4=8 chips.
2. For 36 bit parity SIMM using 1M by 4 bit DRAM chip,
36/4=9 chips.
3. For 36 bit parity SIMM using 1M by 4 bit and 1M by 1 bit
DRAM, the chip count will be 8 data chips(8= 32/4) plus 4
parity chips(4=4/1), total is 12 chips.
4. For 64 bit DIMM using 1M by 16 bit SDRAM, the chip count
is 64/16=4 chips.