I'm building my first computer, & was wondering if a 6 Gb/s SATA motherboard & a 3 Gb/s SATA hard drive can be used together? I already have the hard drive & had a motherboard picked out, but my memory is DDR3 1600, so I need a 1666 motherboard. I can't find any that are 3 Gb/s SATA, only the 6. I didn't know if they were backwards compatible, or if you have to match them up...3 & 3 or 6 & 6. Thanks!