Trends in Computer Architecture

Trends in Computer Architecture

Since the introduction of the first computer, the search for computer architecture that is faster, smaller, and more efficient has been a constant goal of the computer industry. The first computers were large, heavy machines composed of thousands of vacuum tubes. The development of the transistor created the next evolution in computer architecture, the microchip. This is the architecture used in the current generation of computers. Like its vacuum tube predecessor, this architecture of utilizing transistors, can only go so far. Moore's Law predicts that the number of components on a chip doubles every 18-24 months. At this rate each switch will eventually become the size of an atom. When this happens the laws of quantum mechanics must be used. A new evolution in computer architecture will need to be developed to handle the unique laws of quantum mechanics. This architecture is already being developed and is called a quantum computer.

Quantum computers work in a rather distinctive way. Instead of using traditional bits, they use quantum bits, or qubits. These qubits are particles that can take on the unique states required for quantum computing. The best way to understand how a quantum computer works is by example. A basic example is to take a register composed of 2 bits. Using a classic register, these two bits can have a value of 0,1,2, or 3. Now using a quantum register with two qubits, the register can have a value of 0, 1, 2 and 3 all at the same time. Each bit could be in superposition and thus creating every possible value. This unique way of storing values allows a quantum computer to perform calculations at the square root of time it would take a classic computer to perform the same calculation. As the time required for a classic computer grows exponentially, the time required for a quantum computer to execute the same task will only grow at a fraction of the time. (Barenco par. 5)

Quantum computers have made great strides in recent years. They have risen from entirely theoretical to very simplistic implementations. There are still many obstacles that must be overcome before quantum computers become practical. It appears