The Computer Buzz
||June 06, 2006|
Nome and Paul Van Middlesworth - owners - The Computer Factory
More about hard drives
Your selection of a CPU should be based upon how you plan to use your PC. Your hard drive system is also application dependent. For many home or business workstations a single hard drive is all that's needed. A 80Gb hard drive holds about 11 million pages of text. If you entered 10 pages an hour and worked 24/7 you could fill that drive in about 120 years. Problem is that many of us are now filling our hard drives with pictures and songs. "A picture's worth a thousand words," is fairly accurate. That's why hard drives keep getting bigger.
Every hard drive will eventually fail (no mechanical device can run forever), so it is prudent to back up important files. Contemporary PCs have at least a CD-R/W for backing up data. A CD costs about ten cents and will hold 650Mb of data or the equivalent of 450 floppy discs (about ninety thousand typewritten pages.) You don't need to back up operating systems or programs because they can be reinstalled from the original program or recovery discs. Only your data files and pictures are at risk from a hard drive crash.
The multiple hard drive systems that have long protected businesses from data loss due to hard drive failure have become more popular with home users as the cost of hard drives has come down. Today a large (250Gb) secondary hard drive costs about $100.
Last week we discussed a two-drive application. In that application the emphasis was on isolating two or more users from one another. RAID (Redundant Array of Independent Discs) is for a different set of applications. There are seven RAID arrays 0 through 6. For our purposes we will discuss only RAID 0 and 1.
RAID 0 is an array of at least two "striped" drives. The data is spread out across drives "striping" as if the array was a single drive. This improves speed but does not deliver fault tolerance. If one drive fails then all data in the array is lost. This is a popular option for "high end" gamers, animators and other application where very large files are being edited.
RAID 1 is also called "mirroring". In this array each drive is maintained as an exact replica of the other. If one drive fails the other is capable of running all operations by itself until the failed drive is replaced. The good drive is then cloned or "synched" to the replacement drive and the RAID 0 array is reestablished.
External hard drives are another common method of backing up files or the entire system. These drives connect to the USB port and have the advantage off portability. They can be taken of site for added security or they can be used to transfer massive files between computers. A disadvantage is that they cannot be used to operate the computer in the event of hard drive failure.