: Why are computer CPUs the size they are? Wouldn’t making them bigger give way to more processing power without needing better technology?

Question

Edit : My first post to blow up. Crazy.

In: Technology

Answer 1

The explanations posted are good, but I love this question because the actual math is so easy to understand.

Start with how big a processor is, which is **like an inch or two across** right?

Then think about how fast they’re doing stuff. The fastest boast a “4.0 GHz” (Gigahertz), which is the number of operations they can do in a second. That’s **4 billion operations per second**.

But then how long does it take them to do a single operation? Quick conversion, it’s **200 picoseconds**.

Then, we know the speed of light right? c is about **300,000 km/s**.

So the question is, how far can light, the fastest thing around, travel in 200 picoseconds? It turns out, when you crunch all the numbers, the answer is **2.4 inches**. Once you remember that it’s not moving straight it’s gotta wind around in there, it’s easy to see why a processor can’t possibly be bigger than an inch or two across and still run that fast!