If you love using your computer as a workstation and/or gaming platform, then one way or another you may have asked something like this before, “how fast can a computer be?” Not too long ago all a computer really needed to do was a little web browsing and text editing but today computers are absolutely everywhere from watches to massively powerful workstations. The speed of a computer is typically measured in gigahertz, how many billions of cycles a processor can run per second.
Here I have one of the more powerful CPUs available right now, an Intel Core i7-4770K. By default it runs at 3.5 gigahertz which is a very healthy speed but compared to the AMD FX-9590 which can be run at up to 5 gigahertz there doesn’t seem to be too much competition on paper. However not all gigahertz are created equally. As far back as ten years ago processors like the Pentium 4 were capable of speeds approaching 4 gigahertz but put it alongside a modern Core i7 and there’s a massive difference. At a certain point chipmakers started hitting a wall where they couldn’t just keep throwing more and more power at a CPU to make it run faster. To get around this, we now have processors with multiple CPU cores. Having one powerful core is good but having two, four or even eight on a single chip allows a computer to work on lots of things at once. This has worked well over the last decade, allowing computers to get faster and faster by adding more cores however this too has a limit.
Over the last fifty years processors have gotten more and more complex going from two thousand transistors in 1971 to over two billion in modern designs. This constant improvement allows engineers to do one of two things, either take their current designs and make them smaller and therefore cheaper or keep the chips the same size and add things such as more CPU cores. The latest Intel Broadwell technology is based on the 14 nanometer process which is seven thousand times smaller than the width of a human hair. CPUs are going to continue to get faster and add more cores for the foreseeable future however the pace has slowed down as it gets more and more difficult to cram more transistors onto a single chip.
Another important part of a computer are the graphics, known as a GPU. This is what displays video and typically has been in the form of a graphics card like this however companies like AMD have fit powerful GPUs into the same chip as the processor to create an APU. Where a CPU has a few very powerful cores a GPU has hundreds if not thousands of much smaller cores which is ideal for things like gaming and dealing with video. Where things get really exciting is when you look at quantum computers. A normal CPU today has two states, zero and one. On the other hand a quantum computer can work with massive amounts of numbers at once, allowing it to solve problems that would take a normal computer millions of years in a matter of seconds. A company called D-Wave builds what are arguably the first real quantum computers and organizations like Google and Lockheed Martin are already using D-Wave systems to create algorithms to recognize images and test flight control systems. Just like the giant room sized computers of the 1950s quantum computers are in very early stages, requiring a massive box filled with shielding and cooling to keep things stable. Regardless of which technology comes out ahead it’s not hard to imagine a future where a device the size of a smartphone becomes the most powerful computer in the world. The human brain had a good run.