Redundant array of independent memory
A Redundant Array of Independent Memory (RAIM) is a design feature found in certain computers' main Random Access Memory. RAIM utilizes additional memory modules and striping algorithms to protect against the failure of any particular module and keep the memory system operating continuously. RAIM is similar in concept to a Redundant Array of Independent Disks (RAID), which protects against the failure of a disk drive. RAIM is much more robust than parity checking and ECC memory technologies which cannot protect against many varieties of memory failures.
On July 22, 2010, IBM introduced the first (and thus far only) computer featuring RAIM, the zEnterprise 196. Each z196 machine contains up to 3 TB (usable) of RAIM-protected main memory.