Antec TruePower 550w

[Sherlock]

Thanks player0 for reaffirming what I was afraid was the truth: When you're done fooling around, go PCP&Cooling. I just installed mine and I'll never look back. My system's never been this stable.

[Player0]

Cool...glad to hear it

[Nordic]

Originally posted by Player0
...The problem is, the 5v line sags on this default Antec...down to 4.6v using a vCore of 2.1v. This makes things unstable.

Really?
Have you tried measuring the +5V line in a Molex-connector? What the motherboard reports and what the PSU is actually outputting can be two different things.

[Player0]

Nordic,

Yes, they can be different things (but don't go around saying that, some people refuse to beleive it). I have a DigiDoc5 which always reads the molex voltage, and yes, its was always a little higher than what the motherboard reads. (My Fluke DMM always concurred with the DigiDoc when I took manual measurements). Of course, what the motherboard is reading is accurate, but since the motherboard is doing things with the 5v line, it drops the voltage some. The KX7 board was really bad at this. The AT7 I use now doesn't have the same sagging problem, especially when I use the P4 power connector.

Anyway, my Antec 550 is a smoking pile now, and Im extremely happy with my TurboCool 475w which never sags like those Antecs and Enermaxes used too. The voltages are perfect, and I'll never go back to those cheap Antecs again in my main system. Might be time to give Vantec or TTGI a shot.

[Nordic]

My take on the "dropping voltage" thing is that it really doesn't matter unless the voltage drops below the ATX specification of 4.75V. At that point some components might operate .. unrealiably.
But there is a lot you don't see using motherboard monitoring programs and what you can read in the BIOS. Some fluctuations don't appear in the sensor readings and this is when a high quality PSU makes the difference.

I don't get it how you can make the 550W TruePower sag on the +5V line.

I tested an Antec TP 330W on my EpoX 8K7A which ONLY uses the +5V line and it only sagged about 0.05V and 100W cpu power. It was incredibly stable compared to anything I've previously tried.

[Player0]

It all depends on the motherboards really. They all have slightly different on-board powersupplies (dc-dc converters I guess). So some boards react differently than others to certain powersupply conditions. Especially if you do a voltage mod. Abit boards with an overdriven Vcore have extremely bad 5v line sagging. Ive seen them down as low as 4.5v. And actually, the boards were stable like that. Ive also heard lots of reports that on some Epox boards, a 5v line that drops below 4.8v causes major stability issues.

With any switching powersupply, if you draw a lot of current, the voltage will drop. This is what happens on the 3-stage dc-dc converters when the CPU is being overclocked and overvolted, its drawing more current and the voltages all drop (or start to fluctuate which is even worse). You'll even notice a sag on the main PSU itself (although as you mentioned before, it won't be as bad).

Even on my TurboCool 475w, when I plug the 226w peltier on to it, 12v line sags from 12.10v to about 11.90 volts. More current draw will reduce the voltage output (although it takes ALOT of current for this to happen on a nice PSU like the TurboCool).

Abit seems to have improved their dc-dc converter design on the new KT400 boards, as many of the sagging issues are now gone. I imagine your Epox's design has been improved as well, or your maybe not doing any major overvolting yet. The Asus power system has been rock solid since A7V133, I'm glad to see all the other companies finally providing that level of quality.

[spaceboy]

where can i find turbocool?

[Player0]

I got mine from Directron.com

[asw7576]

It works dude..... he.... he.... My PSU is a generic 400 watts ATX version 2.03 ( current PSU model with an extra 12V cable for Intel P4 ). Geeks called it ATX12V. Other ATX version? I don't know. This modification is only for ATX 2.03 where Pin 11 (3.3V) is the feedback wire to PSU.

Cut Pin 11 ( a thinner orange wire ) and insert a schotky diode in between. This is 3.3V feedback wire to PSU, so the direction to put the diode: the "ring" goes toward PSU. Not the other way round. What a schotky diode do? It decreased the feedback voltage from mobo to PSU, and so it forces the PSU to increase 3.3V lines higher to macth the drop reported. My 3.3V now reads 3.53V !!!!

I am warning you: I don't know how much voltage will it decrease by using a scotcky diode, and I don't know either how high your PSU will strike back the 3.3V lines. Do At Your Own Risk!!!