ATX 2.0 psu with -5v????

[nst6563]

I was looking into buying the MSI K8N Neo4 Platinum SLI but in order to utilize the onboard Creative Live 7.1 chip, it needs a -5v line. However, I've been looking on Newegg and various other places and just can't seem to find a PSU that has dual 12v rails, 24-pin ATX, 2.0 compliant with -5V line. Just about everything I've found that has -5v has a 20-pin ATX and a single 12v rail.

advice please I really like the MSI board...and I've read that it can be powered from a standard 20-pin connector just fine...

in any case, if it works with a standard 20pin connector I can use the enermax I have now...but I'd prefer a newer PSU as this one's rails are starting to fluctuate and I've already done some repairs to it (replaced the 90mm fan, also replaced 2 buldging, 1 leaking cap, and a resistor that was losing it's value).

 

[Ice Czar]

not that Im aware of sorry

it was a poor decision to make use of that rail and they got caught with their pants down when the spec changed (v2.01) think it was about 6>7 months ago

 

[nst6563]

crap...
what are the implications of using a 20-pin connector with a high 12v rail (I see some of enermax's 12v rails as high as 33A on the EG465P-VE) and one of those adapters? I'll be using a single 6600GT PCI-E card.

 

[ikellensbro]

Forton Blue Storm has everything you need (which is basically the ATX 2.0 requirement), plenty of amps, and even rounded cables. I love mine to death, everything is nice and solid and sleeved
edit: damn, nvm, Blue storm has +5Vsb, not -5V
you might want to use another sound card if you have it, to offload the sound load on the cpu if a couple frames really matters

 

[nst6563]

Forton Blue Storm has everything you need (which is basically the ATX 2.0 requirement), plenty of amps, and even rounded cables. I love mine to death, everything is nice and solid and sleeved

except the -5v line...


would it be possible to flip a positive 5v line to -5v and then feed it that way?

 

[FreiDOg]

except the -5v line...


would it be possible to flip a positive 5v line to -5v and then feed it that way?

sure it's possible, something like the ICL7660 is a fairly cheap (about 2-3 dollars plus a few passive components) way to get -5V from a 5V line.
or you could splice off the -12V line and use something like the 7905 -5V regulator.

The better question however, and one I don't have an answer to, is: does it matter if you get -5V to the connector? the -5V pin is specified as Not Conneted in the latest ATX specs. Even if you put -5V on it, I have no Idea if the motherboard has the required traces to distribute that to the PCI slots.

 

[nst6563]

sure it's possible, something like the ICL7660 is a fairly cheap (about 2-3 dollars plus a few passive components) way to get -5V from a 5V line.
or you could splice off the -12V line and use something like the 7905 -5V regulator.

The better question however, and one I don't have an answer to, is: does it matter if you get -5V to the connector? the -5V pin is specified as Not Conneted in the latest ATX specs. Even if you put -5V on it, I have no Idea if the motherboard has the required traces to distribute that to the PCI slots.

well, on the Neo4 SLI it *should* be connected since the SBLive chip uses it for whatever reason. so the traces on the board should be connected to the -5v pin...but the psu probably isn't connected (in which case I'd just take out the wire going to the -5v line of the atx connector, and replace it with the output of a circuit generating the -5v ).

I'd be interested in giving that a shot...b/c that blue storm was actually the psu I was going to get.

:EDIT: Was looking at the ICL7660S and it looks simple enough, from what I read in the data sheet, I'd simply need a couple 10uf caps to be able to give it an input voltage of 5v and it generates the output voltage of -5v....however...it doesn't look like it'll handle much current. The 7905 looks a bit more complicated,...but would it be better for the job? I'm not sure how much current that MSI board needs on the -5v line...can't be much though as most psu's have only around .3A to 1A on the -5v line.

thanks for the input too!