"Intel® Rapid Storage Technology offers new levels of protection, performance and expandability for desktop and mobile platforms. Whether using one or multiple hard drives, users can take advantage of enhanced performance and lower power consumption. When using more than one drive, the user can have added protection against data loss in the event of a hard drive failure.
"The Intel Rapid Storage Technology user interface makes creating and managing your storage simple and intuitive. Combined with Intel® Rapid Recover Technology, setting up data protection can be done easily with an external drive.
"Valuable digital memories are protected against a hard drive failure when the system is configured for any one of three fault-tolerant RAID levels: RAID 1, RAID 5 or RAID 10. By seamlessly storing copies of data on one or more additional hard drives, any hard drive can fail without data loss or system downtime. When the failed drive is removed and a replacement hard drive is installed, data fault tolerance is easily restored.
"Intel® Rapid Storage Technology can also improve the performance of disk intensive retrieval applications such as editing home video. By combining from two to six drives in a RAID 0 configuration, data can be accessed on each drive simultaneously. This configuration speeds up response time on data-intensive applications. Also, due to drive load balancing, even systems with RAID 1 can take advantage of faster boot times and data reads.
"Intel Rapid Storage Technology provides benefits to users of single drives as well. Through AHCI, storage performance is improved with Native Command Queuing(NCQ). AHCI also delivers longer battery life with Link Power Management (LPM), which can reduce the power consumption of the chipset and Serial ATA (SATA) hard drive."
As a Lenovo Community user noted, in short, it helps to improve system performance and reduce power consumption for SATA hard disks.
It is recommended that users install the latest version even if you don't use RAID as it contains the drivers for the SATA Controller which is responsible for HDD/SSD operation. Installing the latest Intel Rapid Storage Technology Drivers ensure you have the best performance and transfer rates out of your HDD or SSD.