Question

1. What are the trade-offs between speed, volatility, access method, portability, cost, and capacity with regard to storage for computers.

   1. Specifically the relationship between cost and capacity.

Answer 1

Solution:

There are primarily two types of storage:

Primary Storage:

This type of storage is also called the main memory. This memory unit is usually directly or indirectly connected to the main processing unit i.e. the CPU. The connection is made via BUS wires. The CPU basically executes the instructions stored in the primary storage. The primary storage can be further categorized in three parts:

RAM:

RAM stands for Random Access Memory. The reason behind the name is the data present in RAM can be accessed as fast as randomly. There are two types of RAM:

SRAM which stands for Static Random Access Memory and DRAM which stands for Dynamic Random Access Memory.

SRAM is faster than DRAM and thus is more also more expensive. The power consumption of DRAM is way lesser than that of SRAM. The reason for DRAM being slower than SRAM is ; DRAM needs a refresh of approximately thousand times per second which is not at all required for SRAM; thus making DRAM operations slower.

ROM:

ROM stands for Read Only Memory which is used to boot up the computer. Firmware are stored in ROM chips which stores the instructions for the CPU to perform some of the most basic operations. It is not that easy to overwrite the ROM instructions. In terms of cost and speed they are significantly lesser than that of RAMs.

Cache:

Cache are high speed memory areas used to store the most frequent instructions performed by the computer. This can be a reserved area of a primary storage unit or can be dedicated storage device. In both the cases, this is the fastest memory of the computer and also the costliest. The cache has also evolved with time and now-a-days computer systems come up with L2 and L3 cache; while the older manufactured systems come with L1 cache.

Secondary Storage.

This segment of storage is not directly connected with the main processing unit of the system. Usually termed as the main storage of the system which is accessed by the CPU via various Input and Output devices, they store various kinds of data such as documents, audio or video files etc. in the system as per the user’s wish. This memory is cost effective and moderately faster. Though with time the speed for copying data in / out of the storage has evolved, the price is directly proportional to the storage capacity. The most common secondary storage is the hard disk in the computer systems.