Intel officially confirmed that the ATA TRIM command now work with RAID-0 SSD arrays on some systems running Intel's RST (Rapid Storage Technology ) RAID driver version 11.0 and newer. There are limits off course – it works only on Intel 7 series chipsets with RST RAID support. At the moment only Windows 7 is supported, and Windows 8 support is forthcoming. Why does TRIM Matter?
Each NAND cell has a finite lifespan (determined by the number of program and erase cycles), and although you can write to individual NAND pages, you can only erase large groups of pages (called blocks). In a supported OS, with supported storage drivers and on an SSD with firmware support, the ATA TRIM command is used to optimize read/write cycles and enable more effective use of free space. Enabling TRIM on a RAID array required more effort and Intel finally added TRIM support in its RAID drivers for RAID-1 (mirrored) arrays, but RAID-0 arrays were a different story entirely. Anandtech has done some testing and you can check out the results here.