RAID and SATA: What You Need to Know About Data Storage
Hard drives are the hub of your computer’s operation and memory banks. How many storage disks you use and how they work together is a key factor in determining the overall performance of your system. Learn how RAID disk systems work with SATA III interfaces in a computer system.What does RAID mean?
The acronym RAID stands for Redundant Array of Independent Disks. A RAID system employs two or more disk drives working in concert to facilitate performance and support fault tolerance. RAID systems are classified into rating levels based on how data is handled.How many RAID classifications are there?
There are many RAID classifications based on how the system manages data. Here are some common RAID levels by function.
- RAID 0: Striping evenly distributes data across two or more disks without fault tolerance, parity, or redundancy. RAID 0 is good for high-speed operations such as video editing.
- RAID 1: Mirroring writes an exact copy of the data on the main drive and a secondary or mirror drive. Whenever one drive is replaced, it can be backed up from the remaining drive. RAID 1 works well for small servers.
- RAID 5: Distributed parity works by striping with parity across all drives in the system. With multiple drives in use, RAID 5 offers a balance between efficiency, security, and performance.
- RAID 6: Dual parity means that same parity data is written to two drives instead of one. This makes RAID 6 useful in systems that use large drives.
- Nested RAID: These levels combine the features and functionality of the standard RAID layouts to gain redundancy and improve performance.
Think of a RAID controller as the place where your computer’s servers and storage intersect. It’s used to manage the physical units of storage, delivering them to the server as logical units. The server will see only one drive in the system, but multiple disks work to ensure the drive is backed up adequately. A RAID controller is either an external network attached storage or internal to the server as a RAID card or chip. Many types of controller card interfaces are compatible with RAID technology, including Fiber Channel, IDE, PCI and PCIe, SCSI and SATA.What is SATA?
SATA, which stands for Serial Advanced Technology Attachment, is a type of interface that’s used to connect storage devices to your computer system.
- Overview: Also referred to as Serial ATA, it has a large storage capacity and supports hot plugging. It can transfer data at speeds of up to 6GB when using SATA III. It uses a narrow data cable, up to three feet long. It uses two connectors for data and power. Rather than using jumpers, SATA drives connect directly to the motherboard.
- SATA I: The original generation of SATA runs at 1.5Gbps with a bandwidth of 150Mbps.
- SATA II: This version operates at 3Gbps and the bandwidth level is 300Mbps. SATA II is backward compatible with SATA 1.
- SATA III: The third generation of SATA runs at 6Gbps and supports bandwidth up to 600Mbps. It’s backward compatible with both SATA I and II.