Wednesday, April 27, 2016

DNA hard drives?

A big change may be coming to computing, and a very strange one at that: sometime in the not too distant future, we may find ourselves storing most of our data in biological DNA rather than our conventional silicon and magnetic storage.  I'm in the midst of a two-day workshop that's investigating this possibility, and there's both an interesting prospect and some very big challenges to overcome.

The core idea and concern is that we're just about at the end of what we can do with silicon. For the past fifty years, the density of transistors in silicon-based computing hardware has doubled approximately once every two years, an observation known as Moore's law.  This observation gave rise to a self-reinforcing market structure and the rapid expansion of cheaply available computing has transformed every aspect of our civilization, binding us ever tighter into a connected global society for better or for worse.  That ongoing increase will soon reach the physical limits of what can be achieved with silicon, however, and one of the interesting directions that people are looking to do better is organic materials like DNA.  The theoretical storage capacity of DNA is about a million times denser than flash drive memory, simply because the molecules involved can pack information that much more densely.  To give a sense of scale, that means that you could (in theory) pack one of the gigantic warehouse-complex data-centers that places like Facebook and Amazon build into a single smallish room.

The goal of this workshop is to figure out just how obstacle-strewn is the path between that theory and reality, and figure out whether it's worth pursuing.  This is another one of those interesting life-on-the-interface meetings, with biologists, chemists, computer scientists, information theorists, and silicon specialists all colliding their different viewpoints; with academic theory, government program-building, and corporate pragmatism all sharing a space.

If these DNA hard drives happen, they'll probably be like tape archives, rather than fast computer drives, but they'll be able to store so much information that would still be very useful to consider. There's a fundamental market challenge in that it's not clear whether DNA synthesis technology has enough pull to support the "writing" part of the hard drives.  There's also a long gap between the density of DNA and the realities of making a reliable storage appliance (error correction, packaging, input/output channels, keeping out biological organisms that would like to eat it, etc.), which I estimate will probably cost about two orders of magnitude, giving only about 10,000-fold improvement over the limits of silicon---which is still quite a big deal.

This is not the main direction that I am going with my own research, which is much more about controlling living cells, but it's quite interesting to be asked to be involved in, and close enough that there may be use for the things we've been developing elsewhere.  Plus it's just plain old fun science fiction and I'll be very interested to see just how it can be developed.

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