Yes, you can install just one SATA drive with no need for a RAID array. Although you can overclock most DDR RAM, it isn't a requirement to achieve Dual Channel mode... all you need is 2 DDR chips of the same size and speed (or 3 if your mobo has 3 slots, for example: channel one 2x256 + channel two 1x512 = 512MB in each channel) installed in the appropriate memory slots. The performance gains aren't huge but you'll probably notice a difference when multi-tasking.