Matrix RAID is a computer storage technology marketed by Intel. It is a firmware, rather than hardware or software, RAID system. Matrix RAID first appeared in the ICH6R "southbridge" chip. Intel uses an 'R' at the end of the southbridge's name – ICH9R instead of ICH9 – to indicate when a southbridge contains their Matrix RAID technology and no other upgrades. Complicating the matter is that instead of "R," a "DO," "DH," etc. has indicated a southbridge that combined RAID with non-RAID-related upgrades to the southbridge. Newer chipsets which do not use a separate southbridge might also use Intel RST without explicit extensions like "R" within the chipset name; an example for this is the Intel PCH C200 chipset series. Like all RAID, Intel Matrix RAID employs two or more physical hard disks