[wally774]

I would like to install an Asus Essence STX sound card in a 2008 Mac Pro to use when I boot to Windows under Bootcamp. It's a PCI express card so there's no problem there. However, it calls for an additional 12v power supply. On the card there is a 4 pin male molex, but is there an additional power supply accessible on the Mac Pro? If so, where and what is it? and what kind of connecting cable to use? Thanks.

[P]

That cable you talked about (4 pin molex) delivers 12V and 5V power. You need to run a connector from the existing power supply to that connector. You don't mention power requirements for the card, but the Mac Pro has a fairly beefy power supply, so I don't think there's a problem.

The easiest way to find a connector for that card may be to use one intended for a harddrive or an optical drive. Since they're SATA and the molex you mention is an ATA connector, you need a converter (SATA power to 4-pin molex). If you're out of connectors, you can use a splitter.