Part I: Performance
Capacity
Hard drive capacity is the most simplistic of the factors when looking at a hard drive and also what most companies will try to stress to consumers. Every drive on the market is marketed at a specific storage capacity in gigabyte (GB). One gigabyte is actually 1 billion bytes rather than the literal 1,073,741,824 bytes. What people don't always realize is how the capacity on the actual platters can translate into performance and aesthetics.
Every drive is made of one or more disk platters each with its own drive heads to read and write the information from the platters. Each of the platters has a rated capacity. For example, each platter may be 20 GB. A manufacture can then produce 3 drives all from the same platter by varying the number of platters in the drive to produce 20, 40 or 60 GB drives. Additional platters can increase performance as the number of drive heads to read the data is increased but this also generally translates into a higher ambient noise from the additional platters and drive heads. Also, the more drive platters there are, the more energy that must be expended to turn the platters at the proper speeds. This increases the amount of heat produced by the drive that can actually decrease the overall performance compared to a similar capacity drive with fewer platters. So, more platters does not always mean a better performing hard drive.
Aesthetics
Many people don't realize there are aesthetics to a component that resides inside of a computer. Many manufacturers refer to these as the environmental specifications for their drives. All drives produce two byproducts to their operation just like all other computer equipment, noise and heat.
Anyone who has ever heard an original Apple II floppy drive can attest to the noise a drive can produce. That drive sounded like it was grinding up any floppy that was inserted into it. Now the computer case may dampen the noise, but a noisy drive can be a distraction for some people. In this case, they may sacrifice some performance for a more tolerable computer environment. In general, slower rotational drives tend to produce less noise than higher rotational speed drives. All ratings for a drives noise are listed in decibels (dBA). The higher the number of decibels, the louder the drive is.
The heat byproduct affects aesthetics but can also impact the lifespan of your computer system. All drives generate heat from their operation. Prolonged operation can even cause premature failure of the hard drive. Some of the notorious IBM Deskstar drives were only rated for periodic usage. Prolonged usage of the drives caused the drives to fail due to the excessive heat generated by the drive. This is amplified if the computer case it resides in has poor ventilation to dissipate the heat.
Excess heat can also be detrimental to the user. Computer systems that produce a lot of heat tend to heat their environment. In cold climates this may not be much of a problem, but in warmer climates it can once again reduce the life span of the drive and make it unpleasant to be in the same room. Hard drives are not rated on how much heat the drives produce as a by-product. This makes it near impossible to compare or even shop for in a hard drive.
Part III: Conclusions
