What are the main limitations of primary storage of computer system?

Answer 1

There are three main limits to primary storage of a computer:

1) Physical space

2) Cost

3) Addressable space

Lets address them in more detail

1) Physical Space: Currently traditional hard drives (sometimes called Platter based hard drives) can support 250-500Gigabit / square inch (Approximately 30-60 gigabytes / square inch) . The physically larger drives in desktop computers and servers have platters that are a little larger that 5 inches across for about 19-20 square inches of space for a proximately 1 Terabyte per platter. The ability to have 3 platters in a single full size drive is why you will see 3TB drives at the store. In laptops the smaller 3.5 inch across platters and only being able to support 1 or two platters in a single drive is why you only see 500GB for the slim 8.0mm height drives (only fit 1 platter) and 1TB for the larger 9.5mm height drives (can fit a second platter).

2) Cost: Several companies have developed technology that increase the data density in answer 1, however that technology is extremely expensive to create and would make the hard drives more expensive than any consumer is willing to pay. However as they figure out cheaper ways to make the denser drives, you will see the capacity continue to rise. (This is also why the new super fast Solid State hard drives are so small. They can make bigger drives, they would just cost too much)

3) Addressable space: This is the easiest of the three limits to over come. The change from 32bit to 64bit computing changed this limit from 2 Terabytes to 8 Exbibytes (an Exibyte is approximately a 1 followed by eighteen 0s). The physical limitations should not reach this any time soon.