Theoretical Maximum Transistor Switching Speed (based on distances)

[Skybuck Flying]

Hello,

For a while now I've been wondering what the maximum transistor switching
speed would be.

Today I tried a google but now clear answer came up, so I will try to come
up/calculate an answer myself.

I share it with you for feedback/verifieing/finding any mistakes I made.

For now I will ignore heat problems and other kinds of problems for example
someday somebody might want to build a system that can withstand 1 billion
degrees of heat or whatever.

So for such a situation it would be interesting to see what the maximum
transistor speed would/could be to give some sense of how far away we are
with current/today's technology.

I will make some assumptions:

1. It will be possible to build transistors out of a few atoms. (I suspect
it may even be possible to build transistor within an atom, but for now
that's too much sci-fi ;))

2. The switching speed for a transistor is solely based on the speed of
electrons going back and forth.

So under these simple assumptions the formule to use to determine maximum
transistor (switch) speed seems to be easy:

1. Assume the transistor is 3 atoms thick.

2. Divide this distance by the speed of electricity.

3. Divide this number by 2, to mimic back and forth communication, this last
step maybe not required... but seems more realistic for an up and down
signal or so. A state change/a switch.
(Perhaps this should even be 3... but for now I ll assume 2).

So seems simple enough:

(Minimum Transister Size / Maximum Electron Speed) / 2 = Minimum Transistor
Switch Speed.

So time to plug in some numbers, now it gets interesting... would transistor
speeds depend solely on distances and electron speeds or is there some
hidden third secret limitation/component... for now let's assume not:

http://en.wikipedia.org/wiki/Atomic_radius

According to wikipedia the maximum size of an atom is: 300 picometers

One picometer is again according to same page: 1×10−12 m

I read that as: (10 to the power of -12) meters.

(Window's environment path so full calculator cannot be started, but I start
it via finding it myself. When I enter this into calculator it gives -2 ?
LOL wtf ?!)
(Or I could try 1 / (10^12) = 0.000000000001

I'll use that for now... may have to re-calculate in Delphi or so to see if
it matches... perhaps wikipedia uses wrong notation ? Or perhaps calculator
in windows is too limited oh well.

Anyway... on to the maximum speed of an electron.

I googled a bit and so far current theory seems to suggest maximum speed of
electricity/electrons is near the speed of light. 90% or so

Speed of light is 299,792,458 metres per second.

So now all we have to do is calculate how many times we can go back and
forth, back and forth across our transistor distance and divide that by 2.

((0.000000000001 * 300) / 299792458) = 1.0006922855944561487267301434248e-18

Dividing this by 2 gives:

5.0034614279722807436336507171238e-19

Apperently this is some very smalllllll number. This is exactly how fast a
transistor can switch back and forth.

Now the question is how often can it do this per second assuming there is no
hidden limitation (perhaps such a hidden limitation could be loss of
energy):

To calculate this we would need to divide 1 second by this transistor
switching speed to get hertz, mega herts, gigahertz that kind of thing that
people are used to:

1 / 5.0034614279722807436336507171238e-19 =
1998616386666666666.6666666666667

So let's divide this by mega and then giga and so forth:

http://en.wikipedia.org/wiki/Hertz

For example 1 megaherts is 1 million hertz. So I will use that, I will also
round it down:

1998616386666666666 hertz

1998616386666666 kilohertz

1998616386666 megahertz

1998616386 gigahertz

1998616 terrahertz

1998 petahertz

2 exahertz.

Well surprise surprise... the trees do not grow endlessly forever. Unless
some true science-fiction happens.

We are already halfway the maximum speed of computer technology.

This confirms my hunch that I will live to see the day that it all ends.
Probably right before my death if I grow old enough ;)

I was born when the PC revolution started, and I will probably die when it
ends... though perhaps it will never end... it will just stall.

This little calculation makes me a little bit sad... because 2 exaherts is
not that much... it's still within the 64 bit range.

However it does indicate that our current 4 gigahertz technology is still
far off from what is yet to come.

At least the constants that describe our universal allow for faster speeds.
So there should be some way to achieve that eventually.

Be it by super cooling or other techniques. Super heat resistance materials
or both.

Bye,
Skybuck.

[Skybuck Flying]

After my postings I also googled for maximum cpu hertz to see what it would
show up which lead to:

Besides from a few typos here and there I already found one flaw with the
reasoning from transistor speed to hertz:

In short: transistor speed does not translate into cpu hertz directly
because:

Thanks to the text on this website, which I glanced over and immediatly
understood the problem:

http://www.physlink.com/education/askexperts/ae391.cfm

I won't quote it here but it basically describes that the size of the CPU
matters as well.

The reason is a concept called: "cycles".

A cpu is a complex beast and it needs to do all kinds of things before the
cycle is complete... before it calculated one cycle so to speak.

This means the signals have to go across the chip... across many transistors
and so forth until finally it's all done and one cycle is complete.

Ofcourse I would assume to make a cpu go as fast as possible it would be a
simple as possible chip... to keep these cross over signals as short and as
minimal as possible.

However I think it's pretty easy to see that this would slow down the
maximum speed by a few factors of 10 or more.

So maybe 1000 times slower. Which more or less matches todays transistor
speed at 10 GHz ? (Not researched by it could make sense).

This could mean the actual cpu maximum speed is somewhere between 100
terrahertz to a few petahertz or so.

Bye,
Skybuck.

Below I will correct a few typos at *

"Skybuck Flying" wrote in message news:1e8fe$53979ecc$5419b3e4$***@cache80.multikabel.net...

Hello,

For a while now I've been wondering what the maximum transistor switching
speed would be.

Today I tried a google but no* clear answer came up, so I will try to come
up/calculate an answer myself.

I share it with you for feedback/verifieing/finding any mistakes I made.

For now I will ignore heat problems and other kinds of problems for example
someday somebody might want to build a system that can withstand 1 billion
degrees of heat or whatever.

So for such a situation it would be interesting to see what the maximum
transistor speed would/could be to give some sense of how far away we are
with current/today's technology.

I will make some assumptions:

1. It will be possible to build transistors out of a few atoms. (I suspect
it may even be possible to build transistor within an atom, but for now
that's too much sci-fi ;))

2. The switching speed for a transistor is solely based on the speed of
electrons going back and forth.

So under these simple assumptions the formula* to use to determine maximum
transistor (switch) speed seems to be easy:

1. Assume the transistor is 3 atoms thick.

2. Divide this distance by the speed of electricity.

3. Divide this number by 2, to mimic back and forth communication, this last
step maybe not required... but seems more realistic for an up and down
signal or so. A state change/a switch.
(Perhaps this should even be 3... but for now I ll assume 2).

So seems simple enough:

(Minimum Transister Size / Maximum Electron Speed) / 2 = Minimum Transistor
Switch Speed.

So time to plug in some numbers, now it gets interesting... would transistor
speeds depend solely on distances and electron speeds or is there some
hidden third secret limitation/component... for now let's assume not:

http://en.wikipedia.org/wiki/Atomic_radius

According to wikipedia the maximum size of an atom is: 300 picometers

One picometer is again according to same page: 1×10−12 m

I read that as: (10 to the power of -12) meters.

(Window's environment path so full calculator cannot be started, but I start
it via finding it myself. When I enter this into calculator it gives -2 ?
LOL wtf ?!)
(Or I could try 1 / (10^12) = 0.000000000001

I'll use that for now... may have to re-calculate in Delphi or so to see if
it matches... perhaps wikipedia uses wrong notation ? Or perhaps calculator
in windows is too limited oh well.

Anyway... on to the maximum speed of an electron.

I googled a bit and so far current theory seems to suggest maximum speed of
electricity/electrons is near the speed of light. 90% or so

Speed of light is 299,792,458 metres per second.

So now all we have to do is calculate how many times we can go back and
forth, back and forth across our transistor distance and divide that by 2.

((0.000000000001 * 300) / 299792458) = 1.0006922855944561487267301434248e-18

Dividing this by 2 gives:

5.0034614279722807436336507171238e-19

Apperently this is some very smalllllll number. This is exactly how fast a
transistor can switch back and forth.

Now the question is how often can it do this per second assuming there is no
hidden limitation (perhaps such a hidden limitation could be loss of
energy):

To calculate this we would need to divide 1 second by this transistor
switching speed to get hertz, mega herts, gigahertz that kind of thing that
people are used to:

1 / 5.0034614279722807436336507171238e-19 =
1998616386666666666.6666666666667

So let's divide this by mega and then giga and so forth:

http://en.wikipedia.org/wiki/Hertz

For example 1 megaherts is 1 million hertz. So I will use that, I will also
round it down:

1998616386666666666 hertz

1998616386666666 kilohertz

1998616386666 megahertz

1998616386 gigahertz

1998616 terrahertz

1998 petahertz

2 exahertz.

Well surprise surprise... the trees do not grow endlessly forever. Unless
some true science-fiction happens.

We are already halfway the maximum speed of computer technology.

This confirms my hunch that I will live to see the day that it all ends.
Probably right before my death if I grow old enough ;)

I was born when the PC revolution started, and I will probably die when it
ends... though perhaps it will never end... it will just stall.

This little calculation makes me a little bit sad... because 2 exahertz* is
not that much... it's still within the 64 bit range.

However it does indicate that our current 4 gigahertz technology is still
far off from what is yet to come.

At least the constants that describe our universe* allow for faster speeds.
So there should be some way to achieve that eventually.

Be it by super cooling or other techniques. Super heat resistance materials
or both.

Bye,
Skybuck.

[Robert Baer]

Post by Skybuck Flying
Hello,
For a while now I've been wondering what the maximum transistor
switching speed would be.
Today I tried a google but now clear answer came up, so I will try to
come up/calculate an answer myself.
I share it with you for feedback/verifieing/finding any mistakes I made.
For now I will ignore heat problems and other kinds of problems for
example someday somebody might want to build a system that can withstand
1 billion degrees of heat or whatever.
So for such a situation it would be interesting to see what the maximum
transistor speed would/could be to give some sense of how far away we
are with current/today's technology.
1. It will be possible to build transistors out of a few atoms. (I
suspect it may even be possible to build transistor within an atom, but
for now that's too much sci-fi ;))
2. The switching speed for a transistor is solely based on the speed of
electrons going back and forth.
So under these simple assumptions the formule to use to determine
1. Assume the transistor is 3 atoms thick.
2. Divide this distance by the speed of electricity.
3. Divide this number by 2, to mimic back and forth communication, this
last step maybe not required... but seems more realistic for an up and
down signal or so. A state change/a switch.
(Perhaps this should even be 3... but for now I ll assume 2).
(Minimum Transister Size / Maximum Electron Speed) / 2 = Minimum
Transistor Switch Speed.
So time to plug in some numbers, now it gets interesting... would
transistor speeds depend solely on distances and electron speeds or is
there some hidden third secret limitation/component... for now let's
http://en.wikipedia.org/wiki/Atomic_radius
According to wikipedia the maximum size of an atom is: 300 picometers
One picometer is again according to same page: 1×10−12 m
I read that as: (10 to the power of -12) meters.
(Window's environment path so full calculator cannot be started, but I
start it via finding it myself. When I enter this into calculator it
gives -2 ? LOL wtf ?!)
(Or I could try 1 / (10^12) = 0.000000000001
I'll use that for now... may have to re-calculate in Delphi or so to see
if it matches... perhaps wikipedia uses wrong notation ? Or perhaps
calculator in windows is too limited oh well.
Anyway... on to the maximum speed of an electron.
I googled a bit and so far current theory seems to suggest maximum speed
of electricity/electrons is near the speed of light. 90% or so
Speed of light is 299,792,458 metres per second.
So now all we have to do is calculate how many times we can go back and
forth, back and forth across our transistor distance and divide that by 2.
((0.000000000001 * 300) / 299792458) =
1.0006922855944561487267301434248e-18
5.0034614279722807436336507171238e-19
Apperently this is some very smalllllll number. This is exactly how fast
a transistor can switch back and forth.
Now the question is how often can it do this per second assuming there
is no hidden limitation (perhaps such a hidden limitation could be loss
To calculate this we would need to divide 1 second by this transistor
switching speed to get hertz, mega herts, gigahertz that kind of thing
1 / 5.0034614279722807436336507171238e-19 =
1998616386666666666.6666666666667
http://en.wikipedia.org/wiki/Hertz
For example 1 megaherts is 1 million hertz. So I will use that, I will
1998616386666666666 hertz
1998616386666666 kilohertz
1998616386666 megahertz
1998616386 gigahertz
1998616 terrahertz
1998 petahertz
2 exahertz.
Well surprise surprise... the trees do not grow endlessly forever.
Unless some true science-fiction happens.
We are already halfway the maximum speed of computer technology.
This confirms my hunch that I will live to see the day that it all ends.
Probably right before my death if I grow old enough ;)
I was born when the PC revolution started, and I will probably die when
it ends... though perhaps it will never end... it will just stall.
This little calculation makes me a little bit sad... because 2 exaherts
is not that much... it's still within the 64 bit range.
However it does indicate that our current 4 gigahertz technology is
still far off from what is yet to come.
At least the constants that describe our universal allow for faster
speeds. So there should be some way to achieve that eventually.
Be it by super cooling or other techniques. Super heat resistance
materials or both.
Bye,
Skybuck.

One cannot have a TRANSISTOR less than (about) 100 atoms thick per
junction if bipolar or per doped domain to be more general.
Doping becomes absurd in that ASS-u-ME-ed region; one atom per 10,000
seems to be a low-end doping level which would limit thickness to the
region of 10,000 atoms (adjust for reality).
For the sake of discussion, call it 30,000 and one has a "calculated"
speed ten thousand times SLOWER than your brain fart.

[Maynard A. Philbrook Jr.]

In article <ovPlv.663852$***@fx25.iad>, ***@localnet.com
says...

Post by Robert Baer

Post by Skybuck Flying
Bye,
Skybuck.

One cannot have a TRANSISTOR less than (about) 100 atoms thick per
junction if bipolar or per doped domain to be more general.
Doping becomes absurd in that ASS-u-ME-ed region; one atom per 10,000
seems to be a low-end doping level which would limit thickness to the
region of 10,000 atoms (adjust for reality).
For the sake of discussion, call it 30,000 and one has a "calculated"
speed ten thousand times SLOWER than your brain fart.

Interesting, I didn't know you could measure that or a metric existed
for it ?

Jamie

[David Platt]

In article <ovPlv.663852$***@fx25.iad>, ***@localnet.com
says...

Post by Robert Baer
One cannot have a TRANSISTOR less than (about) 100 atoms thick per
junction if bipolar or per doped domain to be more general.
Doping becomes absurd in that ASS-u-ME-ed region; one atom per 10,000
seems to be a low-end doping level which would limit thickness to the
region of 10,000 atoms (adjust for reality).
For the sake of discussion, call it 30,000 and one has a "calculated"
speed ten thousand times SLOWER than your brain fart.

How about FETs based on graphene monolayers?

It's nowhere near "single atom" storage, but I gather that people have
been demonstrating FETs using single-layer or double-layer graphene
channels.

One article I read indicated that potassium doping of such thin layers
was able to affect the bandgap.

There's some interest out there in other monolayers - e.g. molybdenum
sulphide - which may be superior to graphene.

http://onlinelibrary.wiley.com/doi/10.1002/smll.201302893/abstract

(tunable band-gap MoS)

http://electroiq.com/blog/2012/09/molybdenum-sulfide-the-new-graphene/

"At the upcoming International Electron Devices Meeting (IEDM), an
MIT-led team will describe the use of CVD processing to grow uniform,
flexible, single-molecular layers of MoS, comprising a layer of Mo
atoms sandwiched between two layers of S atoms. They exploited the
material's 1.8 eV bandgap to build MoS transistors and simple digital
and analog circuits (a NAND logic gate and a 1-bit ADC
converter). The transistors demonstrated record MoS mobility (>190
cm^2/Vs), an ultra-high on/off current ratio of 108, record current
density (~20 uA/um) and saturation, and the first GHz RF performance
from MoS. The results show MoS may be suitable for mixed-signal
applications and for those which require high performance and
mechanical flexibility."

[Mike Stump]

Post by Skybuck Flying
For a while now I've been wondering what the maximum transistor switching
speed would be.

:-)

[ .. ]

Post by Skybuck Flying
We are already halfway the maximum speed of computer technology.

Nice. That's one way to view it. But...

Post by Skybuck Flying
This confirms my hunch that I will live to see the day that it all ends.

this does not follow. This assumes that you will use a fix number of
transitors over the entire course of human history and that the cost
for the fix number is fixed. This is not true. First, the number of
transitors you get to use has been increasing and even more
importantly, in terms of an inflation adjusted dollar per transistor,
the price has been falling. The history of technology is we are
asymptotically approaching zero, see google("graph of 1/x"), then
explain how zero makes you sad, as a price for a computer. Compare
price per performance of ENIAC, a PDP-7, z-80 system and new cheap but
powerful Android phone. You will see what I mean. Now find the
limits of technological advancement that would cause us to deviate
from our march to zero. Good luck, I would likely bet against you if
you find any limit.

Curve fit, then tell us how much processing power we will have for
$500 in 20 years. Then come back in 20, and see how accurate that
prediction was.

Anyway, as a sanity check:

http://www.top500.org/files/Supercomputers_London_Paper_HWM_HG.pdf

'In the past, people have said, maybe it's 50 years away, it's a
dream, maybe it'll happen sometime, said Mark B. Ketchen, manager of
the physics of information group at IBM's Thomas J. Watson Research
Center in Yorktown Heights, N.Y. 'I used to think it was 50. Now I'm
thinking like it's 15 or a little more. It's within reach. It's
within our lifetime. It's going to happen.' (IBM, March 2012)

[ disclaimer, that's my office building ]

So, that end (see paper for what that sentence refers to) is 2027 for
compairson to the end you calculated. They do have a 2060 date or so
to hit a single atom on the minimum feature size graph. So, lots of
ends in sight, if all you want to do is focus on the end.

Loading Image...

isn't normallized for price, but if it were, I think the general trend
would be about the same. That one has no end on it, and it is the
only one that matters.

[Skybuck Flying]

You are discussing economy.

In economy there are two driving forces.

Supply and Demand.

You have only looked at supply.

However if there is no demand, no ammount of supply will be "sold".

Even at price zero. Which will probably be somewhat unlikely.

So it will be close to zero. Still not good enough.

If people have to earn 0.00001 dollar to pay for it, they still wouldn't
want it if they have no need for it :)

The demand is from people wanting faster computers.

When computers stop becoming faster this demand will fall away.

That's basically my prediction.

However I also predicted there will still be some demand because of repairs
for broken computers and replacements and such.

But demand will definetly start to fall once computers do not become faster
anymore.

However nobody can predict the future, perhaps there will be other reasons
why demand will rise.

However computers is a bit a broad term.... I will narrow it to "PCs".
Personal Computers that sit on the desk top as we know it... big/large
chunky.

(Perhaps even laptaps and tablets can be counted towards it).

I am not sure what would happen if PCs + Laptops + Tablets + Phones would be
put into a graph.

Perhaps then demand for computers is still up... just PCs only are down.

For now that could mean a shift... perhaps a temporarely shift towards
mobile computers.

However in the end those will probably collapse somewhat as well... however
mobile computers break faster which is kinda ironic :)

Bye,
Skybuck :)