Quantum dots: thanks for the memories

The first computer I used was a Digital Equipment Corporation PDP-9. It had 48K (that's 48KB, not 48MB or 48GB) of wound ferrite core memory that took up half a very large room. The we booted it with paper tape -- a strip of tape with holes punched in it that got read by a paper tape reader. First we had to set some register switches by hand. No time share. We signed up for use two hours at a time. There was someone in the lab 24/7 using the beast. My first desktop, an Apple II+, had the same amount of memory but it fit on a table top. That was 13 years later. Without a monitor it cost $2200. Still 48K of RAM. In the nineties I was on my third for fourth or fifth Apple (by this time a Mac) but I didn't have a hard drive. Mrs. R. had a young kid working for her at the health department who also did moonlighting at a university computer store. As a Christmas present, she had him get her a special deal, 50% off: a 40 MB hard drive. Cost only $1000. Of course now I am sitting in front of a combined monitor/everything else (the iMac form factor) that has 2 GB of RAM and 250 GB internal hard drive and 500 GB external drive, all for far less than my Apple II plus from 1981. What next? Answer: apparently quantum dot memory:

Memory made from tiny islands of semiconductor - known as quantum dots - could fill a gap left by today's computer memory, allowing storage that is fast as well as long lasting. Researchers have shown they can write information into quantum dot memory in just nanoseconds.

Solid-state memory chips - as opposed to hard drives with moving parts - come in two forms. Computers use quick dynamic access memory, or DRAM, for short-term memory. But data does not persist for long and must be refreshed over 100 times per second to maintain its memory.

Flash memory like that used in memory cards and smaller iPods is, despite its name, the elephant of solid memory. It can store data for years without refreshing, but writes information about 1000 times slower than DRAM.

New research shows that memory based quantum dots can provide the best of both: long term storage with write speeds nearly as fast as DRAM. A tightly packed array of the tiny islands - each around 15 nanometers across - could store one terabyte (1000 gigabytes) of data per square inch, the researchers say. (New Scientist)

A terabyte of super fast flash memory smaller than a thumb drive? A terabyte? If I did the back-of-the-envelope calculation right that's about 20 million times as much RAM as took half a room on the PDP-9. And much, much, much faster. And theoretically capable of much faster still, with speeds in the picosecond range (several orders of magnitude faster than now). Instant booting on super light laptops with batteries that last for days?

Of course these memory chips are just prototypes right now. Practical use is still in the future. Which means what? Next month?