World.s Total CPU Power: One Human Brain

[J.A. Terranson]

http://www.wired.com/wiredscience/2011/02/world-computer-data/

By John Timmer, Ars Technica

How much information can the world transmit, process, and store? 
Estimating this sort of thing can be a nightmare, but the task can provide 
valuable information on trends that are changing our computing and 
broadcast infrastructure. So a pair of researchers have taken the job upon 
themselves and tracked the changes in 60 different analog and digital 
technologies, from newsprint to cellular data, for a period of over 20 
years.

The trends they spot range from the expected.Internet access has pushed 
both analog and digital phones into a tiny niche.to the surprising, such 
as the fact that, in aggregate, gaming hardware has always had more 
computing power than the world.s supercomputers.

The authors were remarkably thorough. For storage media, they considered 
things like paper, film, and vinyl records, and such modern innovations as 
Blu-ray discs and memory cards. To standardize their measurements across 
media, they used Shannon.s information theory to consider data storage in 
terms of optimally compressed bits. They also tracked technology, noting 
that in the year 2000, bits of video were compressed using cinepak, which 
was far less efficient than the current MPEG-4 format; calculations were 
adjusted accordingly.

Even so, there are some significant estimations here. .For example,. the 
authors note, .after normalization on optimally compressed bits we can say 
things like .a 6 square-cm newspaper image is worth a 1,000 words...

Similar sorts of estimates are required for things like broadcast 
capability and two-way communications, both of which are compiled as 
bits-per-second figures. The researchers estimate typical consumption of 
broadcast media to figure out how much of the existing capacity is used, 
and they figure that, since telecom equipment is run to maximize the use 
of its capacity, it.s usually booked to close to its limit.

Computing capacity is converted into MIPS, and estimates for the total 
number and class of chips are available. The big question mark here is 
mostly in embedded controllers; it.s hard to estimate both their 
computational capacity and how many are out there.

So these are pretty rough estimates, but similar assumptions are made at 
all four time points examined between 1986 and 2007. That should allow 
comparisons of trends across the time period, even if the absolute values 
of the estimates are a bit off.
Storage

Some trends are very, very obvious. Analog video accounted for over half 
the data stored in 1986 (vinyl LPs and cassette tapes accounted for over a 
quarter), and video held 86 percent of all stored data by 1993, squeezing 
out nearly everything else.

By 2000, CDs and digital tape started pushing back, but analog video still 
stood at 70 percent of all stored data. By 2007, analog video had plunged 
to a tiny six percent, eclipsed by hard disks, Blu-ray and DVDs, and 
digital tape.

During that time, total storage capacity grew at about 23 percent 
annually, and it topped out at 2.9 x 1020 bytes.that.s about 300 exabytes, 
or 61 CDs for everyone on the planet.

A similar shift to digital occurred in broadcast media and two-way 
communications. Back in 1986, 80 percent of broadcast capacity was used 
for terrestrial TV, although analog cable was already a presence. Today, 
broadcast TV has fallen to 50 percent; a quarter of the broadcast data is 
now some form of digital, and analog cable is declining from its peak in 
2000.

Two-way communications underwent a far more dramatic shift. In 1986, 
analog phones handled 80 percent of the data, with digital phones taking 
the other 20 percent; everything else was a rounding error. By 2000, 
analog telephony was down to two percent of the world.s two-way 
transmissions.

Digital telephony peaked in 1993 at 67 percent; fixed Internet connections 
accounted for one percent of usage that year. By 2000, it was up to 50 
percent, and it.s now at 97 percent. Nothing else cleared one percent.

Two-way communications handled 65 exabytes in 2007, dwarfed by 
broadcasting, which sent a whopping 2 zetabytes of data. But, while 
broadcasting is increasing at a linear rate, the advent of the Internet 
has given two-way transmissions a big boost, increasing the bytes 
transmitted by a factor of 29 in just 7 years.
Computation

Computation is probably the most varied mix of hardware of the lot. Back 
in 1986, pocket calculators represented about 40 percent of all computer 
capacity, beating out PCs at 33 percent and servers at 17 percent. Even 
then, gaming hardware held a nine percent share.

Calculators were gone by 2000, when the PC peaked at 86 percent and the 
mobile phone/PDA first appeared at 3 percent. By 2007, phones held six 
percent of world processing power, but the big story was gaming hardware, 
which shot up to a quarter of the total computational capacity, pushing 
the PC back down to a two-thirds share. Supercomputers are apparently rare 
enough not to measure.

One surprising result of the research is the amount of total horsepower 
found in the application-specific space, where the authors considered only 
DSPs, microcontrollers, and GPUs (GPUs alone account for 97 percent of 
this category.s capacity). And that capacity is huge, about 30 times that 
of all the general purpose computation hardware. GPUs account for the 
lion.s share of the 6.4 x 1018 operations a second that the planet can now 
perform, and they showed a compound annual growth rate of 86 percent over 
the study period.

Lest we get too enamored with our technological prowess, however, the 
authors make some comparisons with biology. .To put our findings in 
perspective, the 6.4*1018 instructions per second that human kind can 
carry out on its general-purpose computers in 2007 are in the same 
ballpark area as the maximum number of nerve impulses executed by one 
human brain per second,. they write.

Our total storage capacity is the same as an adult human.s DNA. And there 
are several billion humans on the planet.

Image: Flickr/adafruit.

Citation: .The World.s Technological Capacity to Store, Communicate, and 
Compute Information.. Martin Hilbert and Priscila Lspez. Science, 692-693, 
Feb. 11, 2011. DOI: 10.1126/science.1200970

Source: Ars Technica.