Current ratings a better measure of PS than wattage?

[OS]

I've noticed that the rated wattages on computer power supplies almost seem meaningless, because there are sometimes large differences between the current ratings of two PSs with the same wattage. Example;

Random 340 watt PS

1. +5V 30.0A +5% ~ -5% 50 mV
2. +12V 12.0A +5% ~ -5% 120 mV
3. -5V 1.0A +10% ~ -10% 200 mV
4. -12V 0.3A +10% ~ -10% 200 mV
5. +5Vs 1.5A +5% ~ -5% 50 mV
6. +3.3V 25.0A +5% ~ -5% 50 mV


Enermax 350 watt EG365P-VE(FC)

+3.3V 50mV 4% 32A
+5V 50mV 5% 32A
+12V 120mV 5% 17A
-5V 50mV 10% 1A
-12V 120mV 10% 1A
+5Vsb 50mV 5% 2.2A


In particular, there is a substantial difference between the +3.3V and +12V lines which even the ten watt difference doesn't seem to account for. . .

 

[Kingofcomputer]

yes, don't just look at the wattage.
from amd recommended ps list,
you can see that
cheap 350W ps gives lower combined W than expensive 300W ps.

 

[Rand]

The quality of the build and the specifications on the individual lines are a much better indicator then sheer rated Wattage.
Wattage is little better of an indicator of quality then MHz is for processor speed.

 

[LordOfAll]

You missed an important number there. The 3.3 and 5 volt rails are common. in that I mean there is a combined rating. For example the enermax can drive 32 amps on the the 3.3v or 32 amps on the 5v but not 32 amps to both at the same time. I beleive its common rating is 180 watts.

 

[LintMan]

Interstingly enough, this link to Directron makes the argument to use the PS's *weight* as a rough measure of quality.

From the shopping I've done, it seems that at least the PS's cost correlates pretty closely with the weight, for a given wattage rating.

 

[MplsBob]

LintMan what are you trying to do to us?

Now manufacturers will start filling our power supplies with rocks in an effort to convince us that they make a REALLY GOOD power supply.

"Buy SnootyBarfly Power Supplies, they outweigh all others by at least 10 pounds"

The shipping alone could kill us!


For God's sake don't egg these people on!

 

[LintMan]

LOL - sorry! I didn't say I believed that, just that it was interesting and that heavier PS's tend to cost more.

I'll try not to promote the proliferation of 10 pound power supplies from now on!