"When we tested the ASUS P55 and GIGABYTE P55 boards with USB 3.0 and SATA 6G, we found some interesting numbers when using the GIGABYTE P55A-UD4P in RAID 0. For the most part we didn’t see much of an improvement when going from a single to a dual drive configuration with RAID 0. GIGABYTE also noticed the same issue and quickly went to work with Marvell to find a solution.
When enthusiasts choose to pair a set of drives in RAID 0, they are looking to nearly double their performance. RAID 0 offers many a quick and inexpensive way to get solid performance gains out of the slowest component or subsystem in their computer. Simply put, when your hard storage system is running faster, your entire machine feels more responsive and appears to be faster."