What kind of PC will you have in 2020? If you haven't thought about this before, take a couple of minutes to stick some numbers on the back of an envelope, and see if we agree….
If we look at desktops, I think a decent machine will have a 4GHz quad-core processor, 128GB of memory, 4GB of video memory, a 20TB hard drive, and a Blu-ray writer. The display will be a 24- or 25-inch flat screen, and it will be OLED if we're lucky. I'm not sure if it will have 3D. My estimated price range is £499-£599. Come back in 10 years and see if I was right.
I suspect that you will be disappointed by my projected specification. We live with such rapid progress on a day-to-day basis, it's tempting to imagine dramatic developments over a few decades. By now, we should be living in futuristic cities with flying cars and having honeymoons on Mars. In fact, the real world changes relatively slowly, which is why building societies are offering 25-year mortgages on 100-year-old suburban semis.
As physicist Niels Bohr once quipped, "prediction is very difficult, especially about the future". However, in computing, the numbers get bigger in a relatively predictable way. This was most famously summed up by Intel co-founder Gordon Moore in what has come to be known as Moore's Law. In the April 19, 1965 issue of Electronics magazine, Moore noted that the number of components on a chip doubled every year for roughly the same cost, and in 1975, he modified it to every two years. If Moore's Law holds, then we can predict the computers of 2020 by multiplying today's specification by 32 (2 to the power of 5).
Moore's Law is not a scientific law, like the law of gravity, it's simply an observation. It works partly because technology companies use it to figure out the kind of products they should be able to develop, and when. But the laws of physics and economics intrude. Doubling the number of transistors on a chip now requires working at ever smaller levels, and spending billions of dollars on factories to fabricate them. My numbers are understated by the extent to which I think reality will fail to match Moore's Law.
One particular problem with CPUs is the power they consume and, consequently, the heat they generate. When we used 4GHz Pentium chips with the old NetBurst architecture, some might have predicted that 128GHz chips would be common by now. However, the overheating problem means today's PCs now have lower clock speeds -- typically 3GHz -- but they have two or more processor cores, often with each core running two threads.