Why Do Computers Keep Getting Faster?

Computers have been steadily getting faster, but why is that? Most people shrug and tell themselves that technology is improving so personal computers are simply getting better. This is true, but have you ever wondered why? This is my feeble attempt to try and explain why personal computers keep getting faster in a way that most people will understand.  In my examples I will be representing data as a freight train. Everyone knows what a freight train is and that a freight train carries and delivers cargo from one place to another. The freight train will represent the 1s and 0s that travel around in the everyday computer sitting on your desk.

Speed

Imagine if you will a freight train traveling from NY to LA at 50 MPH. This freight train will take 60 hours to make the journey. But what if the freight train was hopped up and could now travel 100 MPH by improving the tracks, installing a new engine, and improving the aerodynamics of the train? Then the train would only take 30 hours to make the trip. The load of cargo will get to LA in half the time, or 2 loads of cargo could be delivered in the same amount of time as it originally took.

Increasing the speed of a computer gets data to its destination faster. Modern computers measure speed in gigahertz or GHZ. In practical terms a 3 GHZ computer is running 3 times faster than a 1 GHZ computer. The 3 GHZ computer is moving the same amount of data 3 times as fast as a 1 GHZ computer.

Number of bits 8 /16 / 32 / 64

Now imagine a freight train traveling from NY to LA loaded with 100 Toyota Camrys. This train may take 3 days to travel that distance. 100 Camrys are delivered in 3 days.

Now imagine 8 parallel train tracks, each with a freight train loaded with 100 Camrys traveling together from NY to LA. You would now be delivering 800 Camrys in 3 days.

Personal computers started out as 8 bit machines, think of eight freight trains running side by side. Today’s 64 bit personal computers have 64 tracks. The extra speed is achieved by the computer by allowing more data to be transferred around because the modern computer has more tracks.

Multi-core Processors

Maintenance work needs to be done at the train station. The station needs painting, the plumbing needs to be repaired, the grass needs to be mowed, and the station needs a new roof. If Frank does all of this work it will take him 100 hours to do the work. But if Frank had help from Joe then they could split up the work and all of the jobs could be completed in 50 hours.

This is how multi-core processors work.  One core can be running your word processor, and the other can be running Twitter. With the jobs split up the overall speed is increased.

Processor Size

Imagine a map of the United States and on that map NY is 3000 miles from LA. Now imagine if you made the map smaller, NY and LA became closer to each other, now instead of being 3000 miles away from each other they are only 1500 miles from each other. Freight gets to its destination in half the time as it did before.

”Crazy talk!” You may be saying to yourself, but if you looked at the circuitry of a processor under a microscope it would look like a road map with roads and tracks from one place to another. By shrinking the map –thus shrinking the circuitry- speed is increased by shortening the distance between places. This is because data is actually traveling on the microscopic map.  

3D Transistors

If you stacked freight cars on top of each other the 10 freight cars on the train now become 20. They take up as much room on the track but more freight is being transferred at one time.

A new technology called 3D chip technology allows for more transistors in the same space. It’s like having a 3D map that has more stuff crammed in the same amount of space. So it’s like being able to stack freight cars on top of each other.

So there you go, my feeble attempt at simplifying a complex thing. I hope you didn’t fall off of the train and join a hobo camp in the process.