Of memory size, storage space4 min read . Updated: 18 Jul 2017, 05:05 PM IST
How much further can you shrink the transistors on a chip?
Among the assorted Twitter accounts I follow is one called History in Pictures. They post interesting images from the past, a combination of history and nostalgia: of movie stars, musicians, leaders, historical events, trends and just things. I started to follow them (@HistoryInPics) when I saw a photo of one of my favourite actors, Steve McQueen, in one of my favourite movies, Bullitt, taken in 1968. I had a poster of him on my wall when I was young.
Quite a few of the images are famous, and often familiar. If you are as old as I am, you would recognize many of them—the photo of the Beatles waiting to cross Abbey Road (1969); a young girl hitching a ride after Woodstock (1969); Ernest Hemingway on his typewriter in 1939 when he was writing For Whom The Bell Tolls and a 1922 photo of a woman on a beach in the US having her swimsuit measured by a policeman for length violations.
A week or so ago I saw this picture of a huge crate being loaded on to a plane. The year was 1956. The caption said “IBM hard drive being loaded onto an airplane." The size of the hard disk was 5 MB. Just 5 MB. And the box weighed 1,000kg. That’s about a ton. The hard drive was part of an IBM computer that they leased to companies for a fat fee.
Let me try and put those numbers into some context: the average size of a photograph taken by my iPhone 5S is around 2.5 MB (it depends on the photo and the contents). Which means that the giant IBM hard drive was big enough to store just two of my images. A 32 GB pen drive is 6,400 times bigger in capacity and, at just 10g, probably weighs less than an average screw on the IBM drive in the photo.
When a newspaper I worked for in 1995 upgraded its main computer to 1 GB, my son, who was then in school, came to my office only to see what that storage looked like. “One gigabyte. Wow. Can you believe it?" he said. Twenty years on, a hard drive I got for him was smaller than a paperback novel and, at one terabyte (1 TB), had a thousand times more capacity than my suitcase-size office computer.
In early 1990s, when computers started to enter newsrooms, I remember my boss telling me: “The game is all about memory chips. Once they shrink, prices will fall." He took a keen interest in technology, and had an Apple Mac desktop that occupied half his magnificent desk.
Of course, there’s a difference between memory size and storage space; and memory chips cost significantly more than hard drives. My boss was talking about size and price in general, and had obviously heard of Moore’s Law. Gordon Moore, co-founder of the chipmaker Intel, predicted way back in 1965 that the number of transistors in a chip will double approximately every two years. As that happens, computers shrink in size, their performance goes up and price comes down. Stretch that to evolution of technology in general: as it shrinks, it gets better. My first cellphone was huge—and ugly. It wouldn’t fit into my pocket and I was embarrassed to carry it around in my hand.
I remember a vintage ad of “10-Megabyte computer system complete with a floppy drive and a 12-inch monitor". The price was a whopping $5,995 (around Rs3,86,000 now). In comparison, my four-year-old MacBook Air has 256 GB storage and 8 GB memory; and the humble PC a terabyte of space and 4 GB memory. Quite adequate for my needs. Fifteen years ago I may not have been able to afford to double the memory of my PC; today I can because the price has come down.
So far, so good. The question now arises is: are there limits to Moore’s Law? How much further can you shrink the transistors on a chip? We’re talking of areas a fraction of the width of human hair, a gap measured in nanometers (nm), which is one billionth of a meter.
The International Technology Roadmap for Semiconductors (ITRS), a group of experts, says in its report released in July last year that “transistors will stop shrinking after 2021". Beyond that, it is believed that it won’t be “economically viable" to shrink them further. But it also says that “Moore’s Law will probably continue"—in that, the chip-making technology will acquire a different dimension. Innovation never stops and it’s always full of surprises.
I’m not a scientist or a techie, but I am sure that 50 years from now, if @HistoryInPics is still around, someone will post a photo of today’s computers and the generation looking at the photo will say, “How primitive".
Shekhar Bhatia is a science buff and a geek at heart.