In 1943, when the boss of the then virtually unrivalled manufacturer of ‘electronic computers’ powered by vacuum tubes Thomas Watson of IBM was asked how he saw the market for computers, answered: "I think there is a world market for maybe five computers."

He was only out by a few billion on his guess.


In the last decade alone, between 250 and 350 million PCs have been sold every year. With a lifespan of about 5 years that means more than 1 billion PCs are in use around the world today. On top of that we can add tablets, the sales of which in the last two years amounted to about 400 million per year. That adds up to around 1 billion tablets globally. According to Zenith Mobile Advertising, around 66% of the world’s population own a smartphone, making a total of 2.5 billion active smartphones altogether. When you add it all up the number of computers and computer-like devices has grown in over 75 years from just a handful to around 4.5 billion. That’s quite an impressive growth rate.

But that's not all: microcontrollers as integrated systems (CPU + peripherals) have sold more than 20 billion units per year over the past five years. That means for every citizen on Earth there are 15 MCUs. Considering the number of MCUs built into modern cars, it really is no surprise and the IoT has not even started to make a significant impact yet. Greetings to Thomas.Watson@nirwana.heaven.

What does all this have to do with memory cards? Maybe you remember the beginnings of the proliferation of digital technology. The first "real computer" that I had to deal with had a spec that went something like this: 1 KB of RAM, a hexadecimal display, a few push buttons, and a tape interface for mass storage. This was in the early 1980s, and a single-board computer in A3 format powered  by an 8-bit Motorola 6800 CPU was on test at Elektor.

Mass storage

The first PCs and home computers didn’t come with a hard drive. At best, if you had lots of spare cash you could add a floppy disk drive that used disks with capacities from 80 KB to 1.0 MB. The IBM 350 was the world’s first commercial hard disk drive, with a capacity of 3.75 MB – introduced 13 years after Watson's naive estimate. At the start of the 80s hi-end home PCs were using Intel 8086 CPUs running DOS, equipped with a 20 MB 5.25" hard disk drive. Over time their capacity has grown, so today a home computer could be using a 10 TB hard drive.

SD format cards can store many GB of data on a semiconductor wafer the size a fingernail with a thickness of 1 mm. Now that Lexar has cracked the 1TB mark it is a small technical marvel. The Lexar Professional 633x SDHC/SDXC is U3 rated making it really fast — suitable for 4K-capable video cameras: It reads at 95 MB/s and writes at 70 MB/s which is on a par with 2.5" hard drives from a few years back. You will now be able to shoot fairly long videos in 4K without having to constantly worry about whether the memory card is getting full. They will also be a bonus for single-board development platforms such as the Raspberry Pi; with so much space, even more complex operating systems and memory-hungry applications can be developed.