Help Antec TruePower 550W Low Rail!

I just recently upgrade my power supply from Enermax 465P-VE 431W power to Antec TruePower Supply and notice one strange problem. The problem I'm seeing is that the TruePower 550W shows low rails compare to my Enermax 465P-VE 431W.

The wierdest part is that the TruePower is suppose to provide better rail than my Enermax because of more watts then the Enermax. The chart below is the comparison between the two with the same setup.

Enermax 465P-VE 431W
Idle Load
+5 = 5.03 +5 = 4.89-5.00
+3.3 = 3.35 +3.3 = 3.30-3.37
+12 = 11.90-12.09 +12 = 11.78-11.9

Antec TruePower 550W
Idle Load
+5 = 4.80 +5 = 4.67-4.70
+3.3 = 3.10-3.20 +3.3 = 3.00-3.2
+12 = 11.7-11.8 +12 = 11.50-1.60

See what I mean between the two, the Enermax seem to be performing better then the bigger Antec TruePower 550W. Both were purchase as Brand New.

Question, what does the 230V or 115V voltage output mean in the back of the power supply. Can I safely adjust those two setting or what?

Any suggestion is highly appreciated.

I just recently upgrade my power supply from Enermax 465P-VE 431W power to Antec TruePower Supply and notice one strange problem. The problem I'm seeing is that the TruePower 550W shows low rails compare to my Enermax 465P-VE 431W.

The wierdest part is that the TruePower is suppose to provide better rail than my Enermax because of more watts then the Enermax. The chart below is the comparison between the two with the same setup.

Enermax 465P-VE 431W
Idle Load
+5 = 5.03 +5 = 4.89-5.00
+3.3 = 3.35 +3.3 = 3.30-3.37
+12 = 11.90-12.09 +12 = 11.78-11.9

Antec TruePower 550W
Idle Load
+5 = 4.80 +5 = 4.67-4.70
+3.3 = 3.10-3.20 +3.3 = 3.00-3.2
+12 = 11.7-11.8 +12 = 11.50-1.60

See what I mean between the two, the Enermax seem to be performing better then the bigger Antec TruePower 550W. Both were purchase as Brand New.

Question, what does the 230V or 115V voltage output mean in the back of the power supply. Can I safely adjust those two setting or what?

Any suggestion is highly appreciated.

Click to expand...

this is probably a perfect example of how you can not trust software voltage readings....because that antec, unless faulty, is much better than the enermax...

you might also try adjusting the rails on that 550...i think they can be manually adjusted...

but before you do...i would check them with a voltmeter directly from the supply...they might not need adjusting at all...

also...do not adjust the 220v 115v switch...220v is for europe...and will likely fry you power supply

Thanks, but for some reason it is so wierd because both PSU was tested on my same setup.

Thanks, but for some reason it is so wierd because both PSU was tested on my same setup.

Click to expand...

i know...but that's what i mean...the software voltages can still be off even if you change nothing else...you have to use a voltmeter if you really need to know...

but i would say without a doubt that the antec is definitely the better power supply and unless you have problems...then don't worry about it...otherwise use a voltmeter

dustybyrd is VERY correct !

Check your PSU with a MM before you do anything .

Both my (former) IT7 and now my current IC7 mobos showed very low voltage readings with my TP550 .
After testing my TP550 with a MM , my voltages are DEAD on correct . Even at full loads my TP550 only moves by .001 on all of my +12, +5 , +3.3 lines .

Look HERE to see how to test your PSU .


stereo555

thanks guy for all your help. I love this place, everyone is so generous and helpful.

"this is probably a perfect example of how you can not trust software voltage readings....because that antec, unless faulty, is much better than the enermax..."
I was going to say the same.
My friend Christina Mahoney had no problem powering 2 2.2GHz Britney CPUs, lots of drives, and a Radeon 9700 Pro AIW from an Antec Truepower 550.

This has basically been said already, but the only time you should be worried about a power supply is if you voltages fluctuate a lot between load and idle. There is always some voltage lost across the connectors to the motherboard, so technically, the voltages should be lower when measured on the motherboard. Problems arise when they fluctuate a lot. If you look at your enermax power supply voltages, you can see they fluctuate significantly more than the truepower.

Great info!

Hm... So would it be safe to assume that although software readings might not give you a precise voltage, they will give you an accurate estimate as to how much your rails fluctuate?

Great info!

Hm... So would it be safe to assume that although software readings might not give you a precise voltage, they will give you an accurate estimate as to how much your rails fluctuate?

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maybe....but it's also possible that the software either magnifies or minimizes the TRUE voltage fluctuations....

Excellent... My new Antec 480w TP/TB has just arrived! Software readings for my 12v rail are somewhat troubling (11.6 range), but I know better, now. Unfortunately, I've only got an analog multimeter around the house... And it's settings go from DCV @ 10 straight up to 250! There's nothing in between, so I can't accurately measure my 12v line.. >.<

Btw... Does the external molex come standard on Antecs? I assume it's for test purposes, and that's what I used it for. Damn is it ever handy!

the true power 480 and 550 are absolute overkillfor what a system could really use. i have a TP550 and it's insanely dealing with my rig. i could prolly power 2 more identical rigs with it (if possible) and it still wouldn't budge.

You might also consider purchasing a Antec ATX power supply tester http://www.antec-inc.com/pro_details_accessories.php?ProdID=77003 Usually what I do when building a box is test the power supply using the Antec power supply tester with a digital multi-tester…This gives me what I consider the most accurate voltages of the power supply…Then I check the voltages in the BIOS and compare them against what the volt-ohm meter readings are…Then I check them against Mother Board Monitor or the motherboards utility…If the power supply is giving me 12.03 volts with the volt-ohm meter and the BIOS or M/M tells me it is 11.75 then I consider 11.75 to be 12.03…

"the true power 480 and 550 are absolute overkillfor what a system could really use."
A 3.0GHz Britney CPU uses about 130w at stock, a quad Britney machine would use 520w just for the CPUs, so such a machine will require a special PSU.

stereo555 said:

dustybyrd is VERY correct !

Check your PSU with a MM before you do anything .

Look HERE to see how to test your PSU .


stereo555

Click to expand...

I just read that but it says:

If you'd like to also test the 3.3v line, you're going to have to disconnect your power supply from your computer, use a wire trick to power the PSU up, and take the voltages from the motherboard connector.

Click to expand...

Can't you just use the auxilary power connector from your PSU and test it through that, while your computer is on?