Aopen ax5taq Manual De Usuario
Frequently Asked Questions
B-2
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.
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.
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..
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: Why the AOpen mainboards (MB) do not have cache module expansion
slot?
A: Faster CPU speed requires more difficult and complex MB timing design. Every
trace and components delay must be taken into consideration. The expansion
cache slot design will cause 2 or 3ns delay in PBSRAM timing, and the
extended trace length to the cache module through the golden finger will further
delay the timing by 1 or 2ns. This may result in unreliable system once the
cache module and slot becomes worn.
cache slot design will cause 2 or 3ns delay in PBSRAM timing, and the
extended trace length to the cache module through the golden finger will further
delay the timing by 1 or 2ns. This may result in unreliable system once the
cache module and slot becomes worn.
All AOpen MBs support 512KB
PBSRAM onboard. For better performance (around 3% higher than 256KB),
we strongly recommend you to use 512KB onboard. Otherwise, reliable 256KB
is better than unreliable 512KB with cache module. AOpen is the first company
to promote this concept since the fourth quarter of 1995.
we strongly recommend you to use 512KB onboard. Otherwise, reliable 256KB
is better than unreliable 512KB with cache module. AOpen is the first company
to promote this concept since the fourth quarter of 1995.