I just recently purchased a 2 western digital 250gb HDD (http://www.newegg.com/Product/Product.asp?Item=N82E16822144701). I'm setting them up and I have a few questions. I mounted them and the mobo (asus p5b) came with a serial ATA cord that I plugged in to both of them and then noticed there is also a legacy power connector on both HDD's also. So what should I use the SATA power or legacy?