Hardware Raid Keys

**Hardware RAID** is a form of **RAID** (redundant array of independent disks) where processing is done on the motherboard or a separate **RAID** card. **RAID** spreads data on multiple hard disks, balancing overlapping I/O operations. This improves performance and increases the mean time between failures, increasing fault tolerance. The difference in hardware RAID and software RAID is where the RAID processing happens. Software RAID performs the processing on the host’s CPU. Because it does not use the server processor, hardware RAID provides better performance. However, because of the need for additional hardware, it is more expensive than software RAID. With hardware RAID, logical disks are configured and mirrored outside of the system. A physical controller manages the array, presenting data to applications and operating systems as logical units. The controller resides on a PCI bus.