In theory, the computing speed of the human brain can be quantified, but since our understanding of the brain is extremely limited, some scientists have used a very visual metaphor to illustrate how limited our understanding of our brain is:
If it takes a mile to understand our brain, we currently know only 3 inches of the human brain.
Therefore, this work of quantifying the computing speed of the human brain is practically impossible to achieve.
Why do I say that?
Because human beings have about hundreds of billions of brain cells, each brain cell has about hundreds of cranial nerves, each nerve has about hundreds of synapses, and each synapse has hundreds to thousands of proteins.
And more importantly, there are many kinds of signals that one of our neurons can generate, not just 0s and 1s like a computer.
Therefore, with so many combinations, it is impossible to estimate how many combinations there will be.
But there are still scientists trying to estimate the computing speed of the human brain.
Here’s a piece of tech news from January 2014:
As one of the fastest supercomputers in the world, the Japanese supercomputer “K Computer” can perform 8,162 trillion operations per second, with 82,944 processors, capable of driving 1.016 trillion operations per second. But even so, compared with the human brain, “K Computer” is still insignificant.
If must give a visual perception, “K Computer” run at full speed for 40 minutes can only imitate the amount of activity of the human brain for one second.
This is because conducting an experiment that mimics the activity of the human brain requires 1.73 billion virtual neurons to connect with 10.4 trillion virtual synapses, and each synapse requires 24 bytes of memory.
From the old news above, we can see that the computing power of the human brain is actually far better than most of today’s computers, but this news can still only give us a rough idea of it.
How many GHz will the real value be?
American inventor and futurist Raymond Kurzweil did this calculation.
The unit used to describe computing power is called cps (calculations per second).
To calculate the cps of the human brain, you only need to know the highest cps of all structures in the human brain, and then add them up.
Kurzweil takes a professional estimate of the maximum cps of a structure, and then considers the weight of the structure in the entire brain, and does multiplication to get the cps of the human brain. It doesn’t sound like much, but Kurzweil used professional estimates for different brain regions, and the end result was very similar, 10^16 cps, or 100 billion calculations per second.
China’s “Tianhe-2” supercomputer has actually surpassed this human brain computing power. “Tianhe-2” can perform 340 million billion per second. Of course, “Tianhe-2” covers an area of 720 square meters, consumes 24 million watts of electricity, and cost $390 million to build.
But it still doesn’t answer the question: how many GHz is it?
GHz is the unit of the compter’s CPU main frequency, which represents the computing speed of the PC.
If we want to evaluate the speed of a computer, we usually like to look at the frequency of the CPU. For example, 2.3GHz is faster than 2.0GHz.
But the actual CPU frequency is not the only indicator to measure the computing speed of the computer.
The speed of operation also needs to consider parallelism. For example, how many cores does the CPU have？4 cores are definitely faster than dual cores.
This is why the GPU is far superior to the CPU in image processing, because GPU have far more cores than CPU.
Take the classic Pentium4 2.0 CPU as an example, its main frequency is 2.0GHz. Specifically, 2.0GHz means that it generates 2 billion clock pulses per second, with each clock signal period being 0.5 nanoseconds.
The Pentium4 CPU has 4 pipeline operation units. If the load is even, the CPU can perform 4 binary addition operations in 1 clock cycle.
This means that the Pentium4 CPU can perform 8 billion binary additions per second.
In this way, 1 billion billion times is equivalent to 10^16 / 8*10^9=1 250 000 Pentium4 2.0 CPUs, This CPU is single-core 2GHz, so a quintillion is roughly 2,500,000GHz, or 2.5 million GHz.
That is to say, the computing power of the human brain, if estimated, expressed in GHz, is about 2.5 million GHz.