Are you frustrated by slow boot times of your OS or load times of your games? When you transfer or copy files does your computer tell you to just come back tomorrow? Ever since the PC was invited we’ve been cursed with the slowest component in a computer, the hard drive. Even though hard drives have become much bigger and faster, they are still very slow when compared to the other hardware in a computer. Eventually, the hard drive as we know it will have to completely change, but for now we have to live with what is readily available.
Even though hard drives are slowing our computer experience down, there are ways to speed things up considerably. There are a couple easy solutions. The first is to choose a good Serial ATA hard like a 7200.10 (If you have money then 10000RPM Raptors ) SATA 3.0Gb/s HDD and the second solution is to run a couple of these drives in RAID.
What is RAID?
RAID stands for Redundant Array of Inexpensive Disks or Redundant Array of Independent Disks. Simply put, RAID is a data storage scheme that uses multiple hard drives to replicate data among the drives. Depending on the configuration of the RAID or “RAID Level”, the benefits of running RAID can be increased by data integrity, fault-tolerance, throughput or capacity.
Years ago the use of RAID had only been seen in expensive servers. In recent years RAID technology has become inexpensive and readily available to the average computer user. Now days it’s hard to find a motherboard that doesn’t have some sort of RAID offering.
RAID Levels
There are many types of RAID levels, but some of the more popular levels are RAID 0 (Striping), RAID 1 (Mirroring), RAID 0+1 (Striping & Mirroring), and RAID 5 (Block and Parity Striping). Let’s take a look at these RAID Levels so we have a better understanding of what each type does.
Striping (RAID 0)
When a disk array is striped, the read and write blocks of data are interleaved between the sectors of multiple drives (see Figure 11). Performance is increased, since the workload is balanced between drives (or “members”) that form the array. Identical drives are recommended for performance as well as data storage efficiency.
The disk array?s data capacity is equal to the number of drive members multiplied by the smallest array member?s capacity. For example, one 100 GB and three 120 GB drives will form a 400 GB (4 x 100 GB) disk array instead of 460 GB. The stripe block size value can be set logically from 16KB, 32KB, and 64KB. This selection will directly affect performance. Larger block sizes are better for random disk access (like email, POS, or web servers), while smaller sizes are better for sequential access.
Mirroring (RAID 1)
When a disk array is mirrored, identical data is written to a pair of drives, while reads are performed in parallel. The reads are performed using elevator seek and load balancing techniques where the workload is distributed in the most efficient manner. Whichever drive is not busy and is positioned closer to the data will be accessed first. With RAID 1, if one drive fails or has errors, the other mirrored drive continues to function. This is called Fault Tolerance. Moreover, if a spare drive is present, the spare drive will be used as the replacement drive and data will begin to be mirrored to it from the remaining good drive.
Striping/Mirroring (RAID 0+1)
A combination of both above array types. It can increase performance by reading and writing data in parallel while protecting data with duplication. A minimum of four drives needs to be installed. With a four-drive disk array, two pairs of drives are striped. Each pair mirrors the data on the other pair of striped drives. The data capacity is similar to a standard Mirroring array with half of total capacity dedicated for redundancy.
Block And Parity Striping (RAID 5)
RAID 5 calculates parity in order to achieve redundancy rather than writing a second copy of the data, like RAID 1. Parity is distributed across the physical drives along with the data blocks. In each case, the parity data is stored on a different disk than its corresponding data block. RAID 5 makes efficient use of hard drives and is the most versatile RAID Level. It works well for file, database, application and web servers.
JBOD / SPAN
Another popular RAID Array is “Just a Bunch Of Disks” or JBOD. As the name states, it is simply a bunch of disk drives concentrated together to make one large logical drive.
