Miron's Weblog

Update: the BlueGene/L instance used here is only 1/32 of the size of the one deployed at LLNL, so we are still within the high bound after all. On the other hand, it remains to be seen how accurate the model is compared to a functional neuron.

Dharmendra S Modha posts an article about a recent result presented at CoSyNe 2007.

We deployed the simulator on a 4096-processor BlueGene/L supercomputer with 256 MB per CPU. We were able to represent 8,000,000 neurons (80% excitatory) and 6,300 synapses per neuron in the 1 TB main memory of the system. Using a synthetic pattern of neuronal interconnections, at a 1 ms resolution and an average firing rate of 1 Hz, we were able to run 1s of model time in 10s of real time!

This is excellent news, since it will now be possible to figure out what biological modeling aspects are important to functionality.

Since the human brain has 100 billion neurons, this represents 1/10,000 of a human brain. The computer was a $100 million BlueGene/L. So an improvement of 10,000,000 is required in order to model a human brain for $1M in real time.

However, the BlueGene/L is two years old, and it is about 20 times less efficient compared to commodity hardware (based on a quoted 360 teraflops). So the real improvement required is only around 100,000.

Based on this data, the human brain requires 10 Exa CPS, one order of magnitude above the high estimate use in my calculator. Human equivalent for $1M would be available around the year 2023.

Hardware specifically suitable for this application may bring this back to 1 Exa CPS and pull this back to the year 2020.

Tags: Brain, Future, General // 4 Comments »

– Discover has an article about environmental stress (diet, toxins), inflammation and Autism.

– A University of Nottingham study described on the Biosingularity blog shows that autistic children are actually very good at inferring mental states by looking at eyes. This study uses moving images and overturns previous studies where static images were used. I personally find expressions quite readable, yet I used to block them out because the associated emotional charge is anxiety provoking.

– IEET links to an article by Michael L. Ganz that attempts to quantify the cost of autism to society. However, this makes me wonder if the cost is overwhelmingly offset by the contribution of people with Asperger’s syndrome to science and technology. Asperger’s is thought to be a form of high-functioning autism.

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Since I end up figuring these a few times a year, I went ahead and created a little calculator.

It has two fields for year, and calculates the compute powers and ratio. It also compares the compute powers to that required to compete with (or simulate) a human brain.

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Check out this interactive “powers-of-ten” flash presentation from Nikon. Good for some perspective…

Make sure your browser is full screen or you may miss the controls at the bottom.

Hat tip to Nanodot.

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