There are a lot of confusing things to say about disk drives. Capacity, cost, what they actually do… Basically, there are a few drives that you are most familiar with, and they are hard, floppy, external, SCSI, CD, and DVD.

The hard drive reads information off of the hard disk, which uses the same magnetic recording technique as cassette tapes. The information on a hard disk is stored in extremely small magnetic domains. A hard disk can store an amazing amount of information in a small space, and can also access any of its information in a fraction of a second. This makes hard drives very appealing, considering the capacity and speed at which the information can be accessed.

The floppy disk drive contains a few major parts: the read/write heads, the drive motor, the stepper motor, the mechanical frame, and the circuit board. All these parts allow the drive to read the floppy diskette. The 3.5” floppy diskette holds information by magnetism, and the drive reads, writes, and erases the information on the diskette. Because the cost of a new floppy disk drive is considerably less than the cost to fix the drive, there are really no serviceable parts in the floppy disk drives.

External drives work like hard drives, except that you have the ability to move their location. Hard drives are located inside the box and are hard to get to, but external drives are located outside (hence “external”) the box. Depending on the capacity, space, and money you want to spend, you might want to get an external drive.

SCSI (Small Computer System Interface) is a fast communications bus that allows you to connect multiple devices (including drives) to your computer. SCSI drives are commonly used on servers and workstation computers, along with RAID. RAID (Redundant array of independent disks) uses a series of hard drives to increase performance. The hard drives are connected together and treaded as a single entity, which means that the computer sees the series of drives as one big drive. The SCSI RAID controller determines which drive gets which piece of data, and then sends the appropriate data to the appropriate drive. While that drive is writing the data, the controller sends another piece of data to the next drive or reads a piece of data from another drive. All this simultaneous data transfers allow for faster performance.

Two other drives are the CD and DVD drives. There are CD-R’s (recordable), CD-RW’s (re-writeable), DVD-R’s and DVD-RW’s. CD drives can read the CD’s, DVD drives can read DVD’s, CD burners can record or rewrite CD’s, and DVD burners can record/rewrite DVD’s.

Now for cost. From internet research, I found that generally floppy disks cost the least for the most capacity compared to hard drives, CD-R’s, CD-RW’s, DVD-R’s, and DVD-RW’s. So, depending on the capacity that you need and the amount of money that you are willing to pay, you can select which drive that will work the best for you.

posted on 27 April 2003