Question about single rail PSU

[modcon]

I bought a Corsair tx650 PSU to replace the 300W PSU that came in my daughter's HP a6430f computer. This is mainly to run the new PNY 8800GT video card that was also purchased.
I discovered after the fact that it is a single rail PSU, but did not think that mattered all that much since, according to the literature it met the ATX12V spec.
Will this being a single rail PSU be an issue? Is a single rail PSU actually more "dangerous" than a multiple rail PSU or one that is a single rail split into multiple rails?
Jonny's post with the pictures of the melted wires now has me concerned...
Call me overcautious, but I don't want to smoke my daughter's PC and have to buy her a new one!

 

[DSF]

Did you read the sticky on the subject?

 

[IEC]

Ok... What's the bottom line?

The bottom line is, for 99% of the folks out there single vs. multiple +12V rails is a NON ISSUE. It's something that has been hyped up by marketing folks on BOTH SIDES of the fence. Too often we see mis-prioritized requests for PSU advice: Asking "what single +12V rail PSU should I get" when the person isn't even running SLI! Unless you're running a plethora of Peltiers in your machine, it should be a non-issue assuming that the PSU has all of the connectors your machine requires and there are no need for "splitters" (see Example 1 in the previous bullet point).

Should be fine.

 

[mpilchfamily]

FYI a single railed PSU is better then multiple rails. But really there are aguments to support both sides.

 

[modcon]

DSF - thanks for the reply. And, yes, I read the sticky. (And I also saw the 99% post.)

But is a single rail PSU more dangerous than a multi-rail, and if so where would it rank from insignificantly to extremely more dangerous?



It was this post by JonnyGuru in that sticky that prompted my question:

For those who question the validity of the "it's for safety" argument, please have a look at these photos:

http://www.jongerow.com/BFGPOWER/images/DSC02898.jpg
http://www.jongerow.com/BFGPOWER/images/DSC02899.jpg
http://www.jongerow.com/BFGPOWER/images/DSC02900.jpg

I actually see this quite often. Usually with the floppy connector when attached backwards to a Creative sound card or a floppy drive, but this time it was a four pin Molex and it was NOT attached backwards. What it was plugged into shorted and caused this.

The PSU works fine. In fact, if I isolate the exposed wires so they don't short, I can actually hook it up to the load tester and run it.

The short caused the +12V wire to heat up and melt it's insulation off. The wire never shorted so short circuit protection never shut the PSU off. If the PSU had not shut off once the resistance of the short created a > 20A load, the heat would've melted the other wires' insulation, the sleeve, etc.

The first line - "For those who question the validity of the 'it's for safety' argument,.." is what prompted my first post on AnandTech (I've actually been a reader for years even if I don't do a lot of the stuff this site covers.)

I simply want to fully understand the 'safety issue' Jonny mentions. I got the impression that in the quoted post Jonny was talking about the safety of a single rail PSU compared to a multi-rail PSU. I also want to understand the photos. Is this an example of what can happen with a single rail PSU or can it happen with a multi-rail PSU as well? And, yes, I understand the damage was the result of a short. But how common is a short that isn't caused by plugging in a power connector backwards - or to the wrong type of power circuit?

Like I said in my initial post, maybe I'm being a little overcautious. But in addition to not wanting to smoke a PC I also want to make sure I am not putting my daughter at any more risk with the PSU I ordered when compared to a multi-rail PSU. Or, at the least, the risk difference is insignificant.

Maybe I'm doing too much research. And maybe I'm being a worry-wart. But if that is the case it's also something I need to know. lol

Thanks to both you and Spartan Niner for your help. It really is appreciated.

 

[jonnyGURU]

Be concerned if you're going to short out a live lead AND the short has enough resistance to prevent the short circuit protection from kicking in.

How often does that happen?? Umm.... 1 in about a few thousand cases.

Seriously, the odds are really with you. The sticky is meant to clear up the whole "single +12V rail is better... no... multiple +12V rail is better" arguments. Is +12V safer? Sure. Are airbags safer? Sure. But how many accidents have you been in where having an airbag saved your life? Yes, airbags save lives, but people drove long before they were ever developed.

 

[modcon]

Thanks. That's pretty much what I was looking for. Those odds are more than good enough for me!



Maybe I was being too overcautious, but when I'm not sure I always like to ask someone in a position to know.

Quick update:
With the exception of the cables being a bit too long for the case, and also being a bit bulky, IMO, the install went very well and without issue. My daughter can now game to her hearts content.

Thanks again all!