Thread: Need help understanding efficiency and voltage regulation

The power supply i am looking at is the keypower 250 watt. Im just confused on a few things about what the efficiency actually means. And what to do to compensate it. And if i need to worry about voltage regulation.

input: 9 Vdc-18 Vdc 37 A

DC output Characteristics

Output
Voltage V1
+5V V2
+3.3V V3
+12V V4
-5V V5
-12V V6
+5V SB
Max. Load 25A 14A 10A 1A 2A 1A
min. Load 3A 0A 1A 0A 0A 0A
Peak 30A 21A 12A 3A 2A
Total combined output of +3.3V and +5V shall not exceed 125W
Cross
reg.% ±5% ±5% ±5% ±2% ±10% ±5%
Cross
reg.% ±5% ±5% ±5% ±2% ±10% ±5%
Line Reg.% ±1% ±1% ±1% ±1% ±1% ±1%
Ripple & Noise
50mVp-p 33mVp-p 100mVp-p 50mVp-p 100mVp-p 50mVp-p


Efficiency: 60% at typical load
Hold up time: 16ms at full load
Power good signal: 100~500ms
Shout Circuit Protection: A short circuit on any DC output will cause the power to latch.
Over power protection: Peak power protected to between 110% to 125% of continuous rated power.

Over voltage protection: +5V:5.5-6.5V


Teamperture range:
32°F ~122 °F ( 0~ 50°C)
Relative Humidity: Operating: 10~90% rh

Storage: 5%~90% rh

Safety Standards: Meets UL 1950, CSA 22.2 No.234, TUV IEC 950, FCC Class B, VDE Class B

M.T.B.F.: 100k hours at 25°C

Dimention: (W x H x D )
150 x 86 x 142 mm/ 5 7/8"x3 3/8"x5 1/2"

My question is about the 60% efficiency. Does this mean that the power supply will actually be pulling 400 watts to make its max 250? And is the efficiency related to the voltage regulation at all? Will this PSU be susseptible to power spikes? Or do all 12 volt dc to dc PSUs have strict voltage regulation? I have searched on this and ive read so much i went cross eyed and confused myself. I know i need a power controller. Thats a give with this. Just dont know if i will need a seperate voltage regulator or not and what type of problems will i be looking at with only 60% efficiency? THis is basically my last dumb newbie question. Thanks for the help.