Specifications

Frequently Asked Questions
A-11
Q: Why do AOpen MBs use many Electrolytic Capacitors instead of
Tantalum Capacitor?
A: The quality of Electrolytic capacitor has huge difference depends on model
and vendor. Normally, Tantalum capacitor is better than Electrolytic capacitor,
but good quality and high price Electrolytic capacitor is even better than
Tantalum capacitor. Originally, AOpen motherboards use 100uF Tantalum
capacitor nears CPU to reduce voltage ripple, but the technology improvement
has introduced an 1000uF very low ESR (Equivalent Serial Resistor) of
Electrolytic capacitor with only 0.15 ohm comparing with 0.7 ohm of Tantalum
capacitor. The lower the ESR and higher the capacitance value, the smaller
the CPU voltage ripple.
Following are the specifications of capacitors that AOpen is currently using:
Tantalum: SPRAGUE 100uF,
Part number 595D107X06R3C2T,
Max ESR is 0.7 at 25 degree 100KHz.
Electrolytic: SANYO 1000uF,
Part number 16MV1000CG,
Max ESR is 0.15 at 20 degree 100khz.
Also, more capacitors are not exactly equal to better CPU voltage, it depends
on where you put your capacitor (the layout). The most accurate way is to use
storage scope to measure the CPU voltage directly, but of course, it is difficult
for end user to do so. AOpen design team follows Intel, AMD and Cyrix's
design specification strictly, it is approved by Intel, AMD and Cyrix.
Q: What is PC 100 SDRAM?
A: Although 440BX chipset supports 100MHz bus clock, however, it's apparent
that traditional FPM and EDO DRAMs won't be able to work properly under
this system clock frequency. In order to fully support 100MHz or even above
bus clock system, Intel provided PC SDRAM Specifications to facilitate the
development of SDRAM products. This is also known as PC 100 SDRAM
specification. For getting the best performance and stability under 100MHz or
above external clock, we strongly recommand you use the Synchronous
DRAMs which meet the PC 100 requirement. The PC 100 SDRAM that
AOpen QA Team had tested are listed below.
Size Vendor Model Single/Double Chip Count
16M Micron MT48LC2M8A1-08 x1 8
16M TI TMX626812BDGE-10A x1 8
16M Hyundai HY57V168010CTC-10 x1 8