Instruction: Answer the given question by extracting information from the supporting document.

Input:
Question: what is molex cable?
Document: Worked right out of the box; after i restarted my system it just wouldnt boot, i got kinda scared so after several tries I tested switching the molex cable from the PSU, actually i plugged another molex cable into my PSU (Corsair HX-650) and thx god it worked and no problems after that.I love the sound, I'm using it with my Shure SRH-840 and it sounds so much better; more bass and detail, a lot more of soundstage.
Awesome card, but difficult to install at first, because I had to figure out on my own that I had to install the drivers with the molex power disconnected first, and then connect it on reboot after driver install to get any sound out of it whatsoever.
dont know why amazon titled this "124DB Snr Headphone Amp" instead of "xonar essence st" but that is what this is. got this for my vista with sennheiser 595s and they sound much better now. only thing i dont like is that the molex power cord doesnt snap or push firmly into the card.
So I considered this a great investment, since it will handle my future speakers that I'd like to get for my TV as well as all of the fancy bells and whistles in games.Overall, this is a great card and works from the get go. Just remember to plug in the molex power connector, as it won't work otherwise.
for that great 12-foot long cable, and all I had to do was hook up the Toslink to the Logitech Z-5500 Controller Port for Optical hook-ups of the sound system, and BAM! I was done and ready to Rock and Roll, Jazz and Jam, just easy to do and easy to enjoy!And what sound comes out from those speakers! Like WOW!
I have this card running LME49720HA and LME49710HA op amps connected to M-audio speakers with thick gold plated RCA cables. With the stock opamps this card is good. With the LME's this card sounds simply amazing.My power supply is an Antec with very low electrical noise and a large RF choke filter on the card's power cable also.
i had some post purchase, pre-delivery anxiety over spending two hundred dollars on an audio card. it arrived, i popped it in, went to the asus website and downloaded the latest driver, skipping the included disk entirely. installation and setup were quick and easy.i chose radiohead's album king of limbs for the test run because of it's rich field of low, mid and high frequencies. my speakers are logitech z-5500's connected to the card by a higher end monster coax cable.
yet I wanted to ultimately leave you with the impression that if all you want is a killer card the Xonar ST will not disappoint.
this is the card to get when it comes to the dream card you've always wanted. perhaps without spending several hundreds more. this card will bring your setup as far as it can go. some say it's overkill and that a cheaper card is not under kill, but this card will bring you to whatever happy medium your setup will allow. yes, you will not reap the full benefits of the card without the proper equipment.
some also may say it's 'only for headphones' but I disagre, from PC to Amp to Speaker the open air is Hi-Fi. there is no shallow or exploitation between lossy and lossless.one thing that I think is important to keep in mind is, an upgrade will not necessarily make a night and day difference. the same is true with any type of upgrade i.e. television, receiver ect. perhaps in generation of technology. especially in the area of hundreds of dollars difference.
Answer: It's a standard 4 pin male to female connecting peripheral cable found standard with most desktop power supply units. They're used to supply power to just about every thing inside the tower frame. IE: Fans, drives,  audio cards ect. They have white connecting pieces. Here is more info, chances are you have extra ones already inside your tower. Follow link: http://pcsupport.about.com/od/insidethepc/a/molex-pinout-4-pin-psu.htm