How to power a pcie soundcard with 4 pin molex...

paulys55

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Dec 6, 2012
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Just purchased a Asus Essence STXii in hopes of upgrading my audio chain. The card has a 4 pin molex input for power but did not come with a cable. I have tried to power it with a cable that went from the card (4 pin molex) to one of the IDE/SATA power inputs (6 pin) on my PSU but when I try to install the software it says the card is underpowered. Why is it so hard to find a cable to go from 4 pin molex to the 8 pin PCIe outputs on my PSU? and why would Asus not supply a cable or use a different power connector? Any help would be greatly appreciated.

Paul
 
Did you use something like this ?

https://www.newegg.com/Product/Product.aspx?Item=N82E16812422772

I don't recommend using adapters because customers look for cheap, so everybody makes cheap ... and a very high percentage just don't work I have a draw full of them

Might try something like this

http://www.frozencpu.com/products/8768/ele-417/FrozenCPU_Male_SATA_Power_to_Male_Molex_Adapter_PAD05.html?tl=g2c38s261

The FrozenCPU SATA Power to Female Standard 4-Pin Adapter is an adapter to convert your extra SATA power connectors into female standard 4-pin connectors. Got an IDE drive that still takes a pesky molex connector? Don't reroute a molex cable just for that - convert that extra SATA connector and put it to good use!
 
the sound card appears to need a standard 4 pin power cable...every power supply I have seen either has these molex connectors hard wired or available as a plug in accessory. I dont think sata to molex works...only molex to sata used to feed new sata drives from an old molex only power supply.
 
My PSU is a Seasonic x650 Gold. It is modular. There are 3 open outlets (6 pin) for IDE/SATA on the PSU but I tried that and the software said the card wasn't getting enough power. There are 4 or 5 open PCIe/CPU outlets (8 pin) but I don't have a cable that goes from the PSU (8 pin) to the soundcard (4 pin molex) and I couldn't find one on line.
 
Its possible the sound card is defective if you tried to install to a Seasonic molex and it failed...I would suggest trying to install it in another PC if possible just to test it's working. If it fails to install in another PC then it's time to RMA it...
 
The 4-pim molex connector is capable of deliver 5, 7 o5 12 volt power

Pin 1 (12v) to ground = 12 volts
Pin 4 (5v) to ground = 5 volts
Pin 1 (12v) to Pin 4 (5v) = 7 volts

The SATA Connector has 15 pins

(3) 3.3v
(3) 5v
(3) 12v
(5) ground
(1) Undesignated

So the SATA connector is capable of providing the needed voltages, simply by using that same wiring connections as the 4 pin molex as described above

Each SATA pin can carry 1.5 amps so if ya use all 4, that's 4.5 amps. The 12v power pin on Molex was 11 amps ... the 5 I think was lower but I don't recall what the number was.
 


Yes...the CPU and PCIe cables provide different voltages. Your best bet is to power the audio card from a standard Molex connector if at all possible.
 


That is my whole problem...show me a 'standard molex connector' (one that has molex on one end and the 8 pin plug to go into the PSU on the other end...I'm not being sarcastic or coming at you at all, I appreciate all the help, I'm just baffled as to why Asus would sell a product which is supposed to be somewhat high end and not either include a proper power cable or use a more common connection. In my Google search I found at least 4 other threads about the exact same issue and I don't think any of them had a clear solution.
 

I tried using one of the extra cables from the PSU box that had 6 pins on the power supply side and it went to the 4 pin molex but the software said it wasn't getting enough power. So I'm guessing I need to use the 8 pin (PCIe) outlet on my PSU...just was hoping not to have to use an adapter but it seems that is my only option, and I can't even find a good way to do it.
 
From what I recall, the Essence STX had issues with this exact problem once upon a time. I *thought* ASUS fixed that years ago though. Going 6-pin to Molex should work.

If you still have problems, you can give the Xonar Unified Drivers a try; I've heard people have had more success using those drivers. I'm using them on my Xonar Xense without issue.
 
Ok, so it turns out that it was probably working the whole time, I just got derailed by the stupid message prompt from Asus saying "card needs external power cord" or something like that. When I initially installed the card, I used the 6 pin IDE/SATA to 4 pin Molex and when I ran the install disk and got that message I thought I had screwed something up so I aborted the install. Guess that message pops up regardless of whether you did it right or not...pretty stupid if you ask me but its working now and all seems good. Sorry about bugging you guys and thanks for all the help.
 


Makes sense, but yeah, ASUS driver installer has a history of not being the most user-friendly out there.