Redundant array of independent memory
Encyclopedia
A redundant array of independent memory (RAIM) is a design feature found in certain computer
s' 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, but in the case of memory it supports several DRAM device chipkill
s and entire memory channel failures. 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) high end computer server featuring RAIM, the zEnterprise 196. Each z196 machine contains up to 3 TB (usable) of RAIM-protected main memory. The formal announcement letter offered some additional information regarding the implementation:
Computer
A computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem...
s' 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, but in the case of memory it supports several DRAM device chipkill
Chipkill
Chipkill is IBM's trademark for a form of advanced error checking and correcting computer memory technology that protects computer memory systems from any single memory chip failure as well as multi-bit errors from any portion of a single memory chip...
s and entire memory channel failures. RAIM is much more robust than parity checking and ECC memory
ECC memory
Error-correcting code memory is a type of computer data storage that can detect and correct the more common kinds of internal data corruption...
technologies which cannot protect against many varieties of memory failures.
On July 22, 2010, IBM
IBM
International Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...
introduced the first (and thus far only) high end computer server featuring RAIM, the zEnterprise 196. Each z196 machine contains up to 3 TB (usable) of RAIM-protected main memory. The formal announcement letter offered some additional information regarding the implementation: