If the Human Brain Were a Hard Drive, What Would its Storage Capacity Be?

If the Human Brain Were a Hard Drive, What Would its Storage Capacity Be?

June 21

We’ve already discussed whether it will be possible to access the cloud with our brains, but in doing so, we’ve opened up a big can of neurons. One big question is this: if the human brain was a computer, how much storage space would it really have? Would that depend on how intelligent the owner of the brain is? I’m guessing mine can handle at least several thousand petabytes of puppy images, but is that true of everyone? How much data could the average human brain actually hold?

Brains aren’t exactly like computers, though both do handle many computations per second. An article on ThinkQuest theorizes that the brain is capable of about 100 million MIPS (million computer instructions per second), based on some complicated estimations. But there’s no way to actually measure how much processing power a human brain has, and there’s a similar problem when it comes to determining its storage space. There are a few theories, however.

One theory from an article on io9.com explains that there are about 100 billion neurons, and each is capable of making about 1,000 connections that represent 1,000 synapses (synapses do the work of data storage). If you multiply each of the 100 billion neurons by the 1,000 synapses, you get 100 trillion data points, or 100 terabytes of info. The problem with this theory is that each synapse could potentially hold more or less than the one byte of information assumed in this formulation.

The next theory (from the same article) estimates that the brain’s memory capacity is closer to 2.5 petabytes or 2,500 terabytes (equivalent to about three million hours of TV shows or about 2.2 trillion puppy pictures). In the theory we discussed, each synapse was responsible for one data point, but because neurons actually help with many memories at a time, this theory suggests that the number increases greatly because the data isn’t restricted to a single point.

The human brain isn’t exactly like a hard drive either. It’s not prone to filling up, although there must be a point at which it will fill because there are limits to everything physical. Plus, human memory is so prone to fading (I know mine is) that the brain probably keeps plenty of space since not everything is retained indefinitely. The brain is so complex that we’re a long way from discovering all of its mysteries, and we might never actually know how much space it has.

Photo Credit: _DJ_ via Compfight cc