How to distinguish a "REAL" P4 power supply?
A typical P4 power supply should
have following features (EX: 300W)
With
additional 2X2 4P connector
Increased +12V
output
12.0 Amps= > 15.0 Amps
The
reason why +12V demand is increasing for P4 system, the VR current for P4
processor are getting the voltage support from +12V rail instead of +5V
rail.
Increased +5Vsb output
1.5 Amps= > 2.0 Amps
Trends in PC system
power management solutions are driving a need for increased +5Vsb current
capability for all ATX-family power supplies to support IAPC(Instantly
Available PC), STR(Suspend-to-RAM),....functions.
Increased +3.3V output
20.0 Amps= > 28.0
Amps
Trends in motherboard device such as
memory and add-on card are use +3.3V instead of +5V, the +3.3V output
capability should be enhances for current applications and future
requirements.
+5V
min. load requirement was very critical for stability &
compatibility
(The most important)
The reason why to keep +5V output
capability was for downward compatible with traditional ATX power supply
only, last generation ATX & SFX power supply tend to rely on +5V
output to draw a lot of current in order to maintain stable regulation, when
this +5V current dropped to a certain level as on those from a
P4 system, most of the rails may run out of regulation and therefore cause
intermittent failure.
