Computer Chips 101

This post could more accurately be described as "The secrets of Integrated Circuits".  "Integrated Circuit", or IC, is the technical term for what people commonly call a computer chip.  They are the heart of every desktop, laptop, and smartphone.  These devices and many more use all kinds of ICs.  The processor units that computers and smartphones are built around are the most complicated and powerful ICs in existence.  Other ICs can be far less complicated and far less powerful.  Then there are whole classes of special purpose ICs.  But they are all manufactured the same way and all share several important characteristics.  I am going to completely ignore the differences and focus on the commonalities.  In fact, I am going to almost exclusively focus on how they are made.

Don't worry.  I am just going to focus on some key ideas.  It won't require you to have any technical expertise to follow along.  But you will end up with a good overview.  This will enable some surprising insights.  Here's the first one.  The markets for gadgets is supposed to work a certain way.  Take cars, for instance.  If you buy a fancier car it costs more.  And car prices typically increase over time.  I could easily name a hundred other things where the market works the same way.  Fancier is more expensive.  And prices tend to rise over time.  But ICs are different.  Fancier doesn't necessarily mean more expensive.  This is especially true over time.  And over time prices tend to drop for ICs, not rise.  Why is this?

I have been thinking about how to explain this for a long time.  And a long time ago I settled on using picture postcards as the foundation for my explanation.  But between the time I settled on this and now things have changed.  Picture postcards were a part of everyone's shared experience.  I didn't have to explain them.  But the purpose they served for a long time, inexpensively memorializing a place and the fact that you or a friend had visited it, has been replaced by the selfie.  So now I have to worry that when I say "picture postcard" some people will say "what?".

And it's worse.  There is the business of the "picture" part.  In the context of a picture postcard "picture" means a photograph.  But the way people now take pictures has been revolutionized.  Now a digital camera is used, often one that is built into a smartphone.  Understanding how a smartphone takes a picture does not make it easier to understand how an IC is manufactured.  You have to go back to how things worked before digital technology took over the picture-making business.

But with the ubiquity of digital picture-making technology it is also not a given that people understand how things worked previous to this.  So I now feel obligated to throw in an explanation of what a picture postcard is and also an explanation of how photography worked in the time before the digital age.  Fortunately, lots of old movies and TV shows showcase both, so the concepts shouldn't be completely foreign.  Photographs, the non-digital kind, first.

A photograph is in effect a mechanically created painting.  Like a painting there is a supporting medium, something like the canvas painters often use.  In the case of a photograph it is often paper.  But other options like a sheet of clear plastic are available.  And like a painting there is a picture on one side.  In the case of a painting this picture is created by the hand of the artist using, for instance, oil paints.  And the artist frequently introduces various distortions or creates something that never existed in the real world.

With most photographs the idea is to exactly reproduce an image from the real world and to do it without the necessity of someone painting it.  Instead, some very special chemistry and a device called a camera is used.  We seem to have gotten rather far afield at this point.  But from here on out we will head toward not away from our objective.

For our purposes a camera is a simple device.  It has a hollow space inside it and at the back of the hollow space is a film, another word for what will eventually become a picture.  It has a supporting medium, most often paper or clear plastic.  On this supporting medium is spread a thin layer of goo.  A lot of very sophisticated chemistry gives this goo a magical property.  It is photo-sensitive.  If you shine lights on parts of it those parts will have changed chemical properties.  That's the secret that makes it all work.  Special procedures must be used to make sure this special goo is not exposed to light until the proper moment.  The design of the camera assists this.

For our purposes the rest of the camera is quite simple.  It consists of two things.  There is a lens.  The job of the lens is to focus an image from the real world onto the goo on the film.  The image consists of lighter and darker parts.  This pattern of lighter and darker parts is reproduced in the pattern of changed versus unchanged areas of the goo.  The other thing is the shutter.  This is a device that permits light to travel through the lens for only a short period of time.  So you point the camera at a scene you are interested in and trip the shutter. Eventually the scene in question will be reproduced in the picture.

Later the film is removed from the camera and processed.  I am going to skip the details but the result is that the image is "developed" (the part exposed to light change color) and "fixed" (the photograph is no longer changed by subsequent exposure to light).  These subsequent steps are collectively called "finishing" the photograph.  This results in a "negative", a picture where the light parts of the original image are darkened and the dark parts are lightened.  If you "print" the negative (essentially take and finish a photograph of the photograph) you end up with a "positive" a picture of the original image where the parts that were originally dark are dark in the photograph and the parts that were originally light are light in the photograph.

And the process I described above yields a "black and white" photograph.  By what amounts to taking three photographs simultaneously (one for the red parts of the image, a second for the green, and a third for the blue) we can use the same basic process to make color photographs.  "Introduction to photography" is now complete.  What's the point?

Let's say you are on the business of making "picture postcards".  These are cards with a picture on one side, typically of something notable like the Eifel Tower, and a place to put postage, a mailing address, and a short message on the other.  You can buy one, fill out the back side and "snail mail" it to someone.

That used to be the best way to say "I've been to see the Eifel Tower".  Now you can take a Selfie.  With you in the foreground and the Eifel Tower in the background it is much better proof that you were there.  And you can email it or post it on social media immediately.  The level of artistry displayed by the picture postcard is higher.  But the immediacy and convenience of selfies are quickly wiping out the picture postcard business.  But let's ignore all that and go back to picture postcards.

Let's say we want to manufacture a bunch of picture postcards to serve the New York City tourist trade.  (Hang in with me here.  We are about to get to the point of all this.)  We want to give our tourist customers options so we will make postcards featuring pictures of a number of different scenes.  One picture might have of the iconic "LOVE" sculpture.  (It the piece that consists of an "L" and an "O" on top of a "V" and an "E".  The "O" is tilted at an angle.)  The image would be quite simple.  Much of the picture would consist of a neutral background.  Then there would be four blobs, one for each letter.  There would not be a lot of complexity to this picture.

We might decide to use a picture of Broadway during the peak of the afternoon rush as a second option.  This picture would have taxis, other cars of various makes and models, bicyclists, pedestrians, lots of fine detail.  The image here would be a quite complex compared to the one in the "LOVE" picture.  That's all the options I need to complete my explanation so I'll leave it at that.

My point is that it turns out it would cost exactly the same to produce a picture postcard using either of these picture or any other picture we might choose.  We would go through exactly the same process for each option.  We would  start with a piece of paper that had all the stuff we needed on the back.  We would then photograph and finish the appropriate negative to create the picture on the front.  The capital, labor, materials costs, etc. would exactly the same regardless of which picture we chose to put on the front of the postcard.  The only possible place where costs might differ is with the costs associated with procuring the rights to the negatives we want to use.

The secret to why Integrated Circuits keep getting faster, better, and more complex, but the cost stays the same or goes down is that the process of making a simple Integrated Circuit and a complex one is the same.  One might cost more to design than the other but, all things being equal, they are going to cost the same to actually make.  But before diving any further into how ICs are made let's look at why they appeared when they did.

There are certain preconditions that had to be in place before ICs could be invented.  ICs are a type of "solid state device".  The laws governing the operation of solid state devices are called Quantum Mechanics.  So you need to invent Quantum Mechanics in order to be able to invent ICs.  Quantum Mechanics was invented in the nineteen-twenties and -thirties.  Additional refinements had to be added to Quantum Mechanics to be able to figure out how to manufacture transistors and later ICs.  It didn't take long to come up with these refinements.  The first practical transistor was made in 1947 and the first IC followed less than two decades later.

Besides Quantum Mechanics it was also necessary to know how to make super-pure materials.  Twenty-four carat Gold can have impurities representing 1 part in 24 (about 4%).  For most people that's pretty pure.  But there is an even more pure version of Gold called "one thousand fine".  It can only have impurities representing 1 part in a thousand (0.1%).  When it comes to purity, that's about as far as most people's imagination takes them.  But it is far from pure enough to make transistors or ICs.  The least pure materials you can use can only have impurities representing 1 part in a billion.  That's a million times as pure as "thousand fine" Gold.  And for may applications that's not pure enough.  The purity must be taken up another thousand or million fold.  So how do you purify something to that extent?

There's a trick.  Melt the material but keep it just barely hot enough to stay liquid.  Then slowly dip a rod of the same material into the liquid so it is barely touching the surface.  Finally very slowly withdraw the rod.  If you are careful enough very pure material will solidify on the end of the rod causing it to grow.  And the material that grows on the end of the rod will be much purer than either the material in the un-melted part of the rod or in the original pool of liquid.

So you repeat this process.  You draw rods using your originally pretty pure pool of material.  Then you melt the fresh parts of those rods together into a new pool.  The material in this new pool will have far fewer impurities.  If you then draw new rods the fresh part of these rods will be even purer.  If you repeat the process carefully enough and enough times you can create super-pure samples of the material.  And there's a kind of a shortcut you can start using once you have drawn the first set of rods.

You build a special furnace that tightly surrounds a rod.  For most of its length it keeps the rod just below its melting temperature.  But the furnace has a hot spot where it heats the rod to just above its melting point.  If you draw a rod slowly thorough this special furnace you can slowly move a melted area from one end of the rod to the other.  The material melts and re-solidifies as the rod goes through the furnace and past the hot spot.  This concentrates the impurities in the melted part resulting in an increase in purity for most of the length of the rod.

Of course, you eventually end up with a piece on the end of the rod where the impurities are now concentrated.  You just cut that part off and throw it away.  By repeatedly applying this "melt then re-solidify" process you can make rods of extremely pure material.  Companies that specialize in this process have gotten quite good at producing super-pure materials at a surprisingly low price.

Making transistors and ICs depends on an attribute of some materials called semiconduction.  Elements like Copper that are "conductors" of electricity.  Electrons flow freely through them.  Elements like Sulphur are "insulators".  It is nearly impossible for electrons to move around in them.  And an electric current is just electrons flowing.

There are a few special elements called semiconductors that in some circumstances behave like conductors.  But in other circumstances they behave like insulators.  It is possible to manipulate these circumstances on the fly.  This means that at one time one pattern of conductor here and insulator there can be set up.  But a short time later a different pattern of conductor here and insulator there can be set up.  This capability lets ICs do magical things.  With modern ICs circumstances can be changed more than a billion times per second.

The key to this ability to manipulate circumstances is to start with a super-pure semiconductor.  Then a process called "doping" is used to introduce tiny amounts of specific impurities into very small selected areas of the surface of the IC.  Quantum Mechanics tells us that if we have the correct configuration of pure semiconductor and doped semiconductor we can create various kinds of electronic components.  These components can be wired together to perform arithmetic and all the other things a computer (and many other electronic devices) need to be able to do.  An IC is just a whole lot of these components wired together to fly in close formation.

The two most common semiconductors are Silicon and Germanium.  Germanium is relatively expensive and hard to work with.  Silicon, on the other hand, is cheap and much easier to work with.  It is the eighth most common element and is the primary component of beach sand.  Most ICs are Silicon based for cost and convenience reasons.  But Germanium or mixtures of Silicon and Germanium are used in some specialty situations.  And research leading to ICs made from other materials is an active area of investigation.

Okay, so how are ICs made?  The process starts with a rod of super-pure semiconducting material.  It is sliced into very thin "wafers".  Each wafer is processed individually to make many identical ICs at the same time.  Eventually each wafer will be sliced up into many individual ICs.  It is the middle "processing" part that is the interesting part so that's the part I am going to focus on.  And the processing part is an elaboration of the process I outlined above for making pictures.

In the case of the IC the part of the paper or clear plastic is played by our wafer of super-pure semiconducting material.  With a black and white picture we go through a single processing cycle.  We may go through three cycles to make a color picture.  Typically an IC will require many more cycles, sometimes dozens.  But each cycle is just an elaborate version of the processing cycle used for pictures.

At the start of each cycle we first spread some special goo on our wafer.  Then using a bright light, a "mask" (this is what provides the image), and a lens, we project an image onto the goo.  Then we go through a "finish" step.  With photography the finish step is always pretty much the same.  With a color picture we may need to go through a "red" cycle, a "green" cycle, and a "blue" cycle.  But all three cycles are pretty similar.  In the case of ICs things are a bit more varied.  Many more cycles may be necessary and the processing that takes place within a specific cycle varies much more widely than it does with our "red", "green", and "blue" cycles.  But it's the same idea.

The simplest IC process involves doping.  This consists of introducing small amounts of very specific impurities into the semiconductor.  These impurities come in two general classes, P-type impurities and N-type impurities.  The differences are not important to this discussion.  But if the correct pattern of P-type impurities, N-type impurities, and unmodified semiconductor is created in the top layer of our wafer then they work together to create a "gate" or other IC component.  In another process lines of material, most commonly silver or aluminum, are laid down to connect one component to another like a wire would.  In still another process trenches are "etched" into the silicon to separate one component from another.  There are a few more types of cycle but you get the idea.

Repeating myself, the details of each type of cycle are different but the general idea is the same.  A layer of goo, the specifics of which depends on the effect desired, is laid down uniformly over the surface of the wafer.  Then an image of a "mask" is photographed on top of it.  This changes the chemical properties of the parts of the goo that have been exposed to light.  Then another layer of goo is laid down.

This second layer of goo interacts with the first layer of goo .  It may either interact with the parts of the first layer that have been exposed to light or the parts that have not.  The interaction between the two types of goo may result in areas being "doped" with an impurity.  It may result in a line that acts like a wire being laid down.  It may result in a trench being etched in the material.  Whatever changes are necessary to create the IC are made processing cycle by processing cycle.

Typically a cycle finishes with a process that cleans away any unwanted remaining material.  This sets the surface of the wafer up for the next cycle.  Cycle follows cycle until all the layers of patterns necessary for the device to function have been put down on top of the supporting medium.  At this point each device is complete but it is still necessary to cut up the wafer to separate each IC from all the others.

It requires a high degree of knowledge and skill to design the "component layout" on the IC.  It requires a high degree of knowledge and skill to figure out what manufacturing steps (the processing cycles) are necessary.  Then machinery of extremely high precision must be designed, built, and operated to actually produce the ICs.  But I will leave those details aside and move on.  Except that I note that a "fab", a factory for manufacturing ICs, typically costs more than a billion dollars to build.

So the process is essentially the same for all ICs.  ICs with a lot of components require extreme precision machinery to manufacture.  But once the manufacturing process has been set up this has no effect on the "unit cost", the cost to make another identical IC.  And a tiny amount of material goes into each IC.  So material costs contribute little to the cost of the IC.  One factor that does effect unit cost is how many processing cycles are necessary to create the proper components with the proper connections on the IC.  But all ICs that require the same number of processing cycles cost essentially the same.

And the system is set up to make millions of identical ICs.  If you make a million ICs in a billion dollar fab then the fab cost-per-IC runs to $1,000.  That means each IC must be priced at more than $1,000 and that's expensive.  But if you turn out a hundred million ICs, a figure commonly reached over the five year prime lifetime of a fab, then the fab cost-per-IC is $10.  The rest of the process is relatively inexpensive so the fab can make a nice profit turning out chips with a wholesale price of $25 each.

And a fab is not worn out after five years.  Its just no longer a cutting edge facility.  But lots of ICs do not need to be made in a cutting edge fab.  So if the fab that is no longer cutting edge is shifted over to turning out these "commodity" ICs, and it frequently is, then it may now be possible to use that fab to profitably produce ICs that can be sold for far less, perhaps less than a dollar each.

The fact that ICs are made using photographic processes is the big secret to why the IC market behaves so differently than the market for most products.  That's the biggest of the IC secrets.  But there are other, lesser secrets so let's get into some of them.  Another secret has to do with component size.  As the industry has matured it has figured out how to make each component part of an IC, often referred to as a "gate", smaller.  This seems like a good idea in general.  But it turns out to have valuable benefits that are not immediately apparent.

Let's say we want to make an IC with a million components in it.  Then if each component is relatively large the resulting IC will be relatively large.  But there are practical limits on how large you want to make an individual IC.  Turn the relationship around.  If we are making an IC of a certain size then the component size tells us how many components it can have.  Remember, it doesn't much matter how complex the design is.  It still costs about the same amount of money to make it.  So as we reduce component size we can increase the component count and keep the IC size constant.  Components are now so small that some ICs that have tens of billions of components in them.

To recapitulate, fabs use rods of semiconductor, usually Silicon, as their starting ingredient.  These are sliced into thin wafers.  If we can use very small components then we can manufacture a small IC.  And we don't make a single IC from a single wafer.  Instead we divide the surface of the wafer into small rectangular areas and create an identical IC in each rectangle.  The entire wafer is simultaneously subjected to each processing cycle.  So one set of cycles produces many ICs at the same time.  As we make each IC smaller we can fit more of them on a single wafer.  So we can now make more ICs for the same amount of money.  This reduces the cost-per-IC.

In the race to continuously speed ICs up the speed of light is a limitation.  It limits how fast signals can propagate across an IC.  It is a fixed number.  If we make the components smaller then we can put them closer together.  This means the finished IC goes faster because propagation delays, the time it takes for a signal to get from one place to another, are smaller because the components are closer together.  This means we can make an IC faster without changing its design.  All we have to do is make the components (and the final IC) smaller.  For a long time this was one of the big secrets that explained how the industry could keep making their ICs go faster and faster.  They didn't do anything clever.  They just kept shrinking the component size and that reduced propagation delays.

In the early days making components smaller was relatively easy.  You just had to be more and more careful.  But it didn't take long for some interesting problems to start cropping up.  It turns out that you can't focus light infinitely sharply.  There is an inherent limitation based on the wavelength of the light you are using.  At first ICs were manufactured using regular white light.  White light was used because it was the easiest kind of light to come by.  And it worked fine until the components shrank to a certain size.  White light is composed of lots of wavelengths.  That blurred things.  When components were relatively large this blurriness could be ignored.  But at some point components shrank enough that the blurriness started to get in the way.

The obvious fix was to use a light consisting of a single color.  It was easiest to do this with red light.  And that worked for a while.  Red light was sharper than white light so it was an improvement.  But red light has a relatively long wavelength so red light became a no-go when components shrank some more.  Blue light has a shorter wavelength than red so blue lights were used until further shrinkage caused blue to also become a no-go.  Ultraviolet light has a still shorter wavelength so ultraviolet lights were switched in.  And they too worked fine for a while.

But that is pretty much the limit.  The obvious next step would be to go to X-rays.  They have still shorter wavelengths.  But masks by their very nature are full of extremely small details.  After all, they determine the exact shape and location of each part of each component.  Making a mask that has the requisite small detail and stops X-rays has so far proved to be impossible.  So ultraviolet is as good as it gets unless someone comes up with a true breakthrough.  So component sizes can't shrink to the point where they are too small to be manufactured using ultraviolet light.

And it turns out there is another, really strange problem that crops up as you make components unbelievably small.  That is Quantum Mechanics.  It turns out Quantum Mechanics giveth and Quantum Mechanics taketh away.  Quantum Mechanical makes it possible to design and create ICs in the first place.  But new Quantum Mechanical effects come into play when you make components unbelievably small.  Mostly we don't care how many atoms something contains.  That's because even something extremely small still has a fantastically large number of atoms in it.  If lots of atoms are involved then "bulk" Quantum Mechanical effects determine behavior.

But components have now gotten so small they may contain only about 10,000 atoms.  That is where "small scale" Quantum Mechanical effects come into play.  The fewer the number of atoms the greater the small scale effects.  One of these effects is called "tunneling".  If we have a thick insulating barrier the electrons stay on one side.  But if the insulating barrier is thin enough a certain percentage of the electrons "tunnel" through the barrier and end up someplace we don't want them to be.

How thin is thin?  Typically if we have a 10,000 atom component partly surrounded by an insulator only a few electrons will tunnel through the insulator.  But as the atom count drops the percentage of electrons that succeed in tunneling through rapidly goes up.  Components are designed so that they can tolerate a small amount of electricity straying into places where it isn't supposed to be.  But at some point the component stops working properly if the amount of stray electricity gets too high.  No one has been able to figure out how to design components that work properly when they are so small that that tunneling and other small scale effects have to be taken into account.  The solution so far has been "don't go there".  In other words, don't shrink component size to the point where small scale Quantum effects come into play.

These effects are well understood but neither designers nor manufacturers have figured out how to get around them.  The result is that the march toward smaller and smaller components has been drastically slowed.  And this means that the march toward faster and faster components has also been drastically slowed.  Moore's Law predicted that processor speeds would double about every two years.  And for decades they did.  But processor speeds are now little changed from what they were ten years ago.  The dual problems of shrinking components below their current sizes and the design problems caused by small scale Quantum Mechanical effects have combined to bring improvements to a nearly complete halt.

There has been some progress.  But mostly what has happened is that your economy model whatever now has about the same performance as the high end model of five or ten years ago.  This has resulted in PC sales being flat to down.  Why replace an old PC if a new one doesn't go any faster or do anything the older model can't?  For a while laptops and tablets were showing robust sales numbers.  Not so much now.  Again the performance difference between new models and those of a few years ago keeps shrinking.

And the smartphone is now ten years old.  In the early years the new models were much better than similar models from only two or three years previous.  But even the rate of improvements in smartphones has now slowed dramatically.  Manufacturers "maxed out" the performance of PCs first.  Then came tablets and laptops.  Now the same thing is hitting smartphones.

All these devices use ICs.  Power and space requirements were the loosest for PCs so manufacturers found them the easiest to max out.  Specifications are a little tighter for tablets and laptops so manufacturers of ICs for these devices took a little longer to max them out.  Specifications for smartphones are the tightest of all so ICs for these devices got the treatment last.  But they have now gotten the treatment.  The result is a new smartphone that is not much better than the smartphone of a couple of years ago.  Far too many people are now happy with a phone that is one or two generations old.  This is a growing concern among smartphone makers.

What is driving all this is are fundamental laws that can't be easily gotten around.  These limitations that are now inhibiting rapid improvement.  So what's the new,. new, thing?  People have been talking about a couple of things.  Current electronic devices are built out of ICs.  And ICs work by pushing electrons around.  How about replacing electrons with light?  It's the fastest thing in the universe and about three times as fast as electrons moving through wires.

Devices that use light instead of electrons are called "photonic" devices.  There has been a lot of work done in this area.  But no one has been able to figure out how to make a photonic device with more than a few components.  (Remember, processor ICs now have tens of billions of components.)  And light travels in a straight line while electrons are happy follow a bendy wire.  This and other problems have led to photonics being restricted to a very few highly specialized areas.  There seems little chance that will change any time soon.

The other area receiving a lot of attention is Quantum Computing.  Standard computers behave in a "sequential" manner.  They do this then they do that then they do the next thing.  Things proceed a step at a time in sequence.  There are limited exceptions to this.  There are such things as "parallel" computers.  And super-computers are "massively parallel".  But that is somewhat of a cheat.

Parallel computers consist of a few (normal computer) or a whole lot (super-computer) of regular sequential computers all hooked tightly together.  If all these sub-computers are contributing usefully to the solution of the main problem then then these parallel computers will solve that problem way faster than a standard sequential computer could.  This would make everybody happy.  The problem is to get all those sub-computers to contribute productively.  This is called the "partitioning" problem.

If a problem can be partitioned into a number of parts and each part can be assigned to its own sub-computer that can just focus exclusively on that one part while ignoring everything else then a parallel computer can get to the solution much faster than a sequential computer.  Well, there is another thing.  It can't take a long time to do the partitioning on the front or the assembly on the back.  Otherwise, the benefit of doing the middle part quickly will be lost to the cost of doing the front and/or back slowly.

In short, it turns out that partitioning problems is often hard.  In fact, there are lots of problems where no one has figured out how to partition them.  There are only a few super-computers in the world.  There are enough problems that have successfully been partitioned to keep them all busy.  But first let's take a look at a couple of problems that are suited to PCs and other computers that are capable of a relatively modest amount of parallelism.

One PC sized problem that is easy to partition is "rendering" all the stuff we throw up onto our computer screens.  Gaming PCs have a dedicated high end video card.  These cards can do a lot of partitioning and do it very well.  That is a good thing because these cards also feature multiple "graphics processors" that can and do work in parallel.  Gamers prize the improved video experience and are willing to pay for it.  A more limited version of this capability has already started moving down the food chain.

The video IC that came built in to the inexpensive PC I bought a couple of years ago is every bit as capable as were high end video cards from several years ago.  It has a significant amount of parallel processing capability.  And similar ICs are showing up in tablets and laptops.  If they are not already there I'm sure they will soon be found in smartphones.

At the other end of the process, many web pages have multiple components and sub-areas.  It is relatively easy for a good browser to partition all this out and assign each part to a separate sub-processor on a PC.  My main PC has 8 sub-processors.  Most modern PCs, even the inexpensive ones like my newer one, now have at least two.  This allows web pages to load faster.  Unfortunately, a good deal of what loads faster is advertising.  Oh well.

Unfortunately, few other PC tasks partition well.  The same is true for applications that run on laptops, tablets, and smartphones.  A few applications partition well but most don't.  That's why the industry has stopped talking about how many processes a machine can run at the same time.  A higher number generally doesn't result in an improved user experience.  Turning to super-computers.

Weather forecasting turns out to partition well.  That's why so many super-computers are used for weather forecasting.  Meteorologists have figured out how to partition a weather forecast into pretty much as many parts as they want.  If a super-computer with 10,000 sub-processors is available then the forecast is partitioned into 10,000 parts.  When super-computers with 100,000 sub-processors become available they will just partition a forecast into 100,000 parts.

Computer Scientists are getting better at figuring out how to efficiently partition more and more types of problems.  But it is slow going.  There are many more types of problems where they haven't figured out how to partition than there are problems for which they have.  Alas, a problem that does not partition well will run no faster on a super-computer than it will on a regular computer.

100,000 is a large number.  But there are problems that can be partitioned into millions, billions, or even vastly more parts.  Cracking encryption schemes is one of them.  If you can check billions or trillions of keys at once than you can find the key to a particular encryption that would take a super-computer with 10,000 sub-processors an impractically long time to crack.

Quantum Mechanics provides a possible way to solve some problems that would otherwise not be soluble in a reasonable amount of time.  Stories in the press about this sort of thing mix two quite different methods together.  One approach is good for problems where massive partitioning is helpful.  The other approach  depends on Quantum Mechanics but is not appropriate for massively parallel problems.   I will take them separately.

What if it was possible to arrange things so that billions and billions of molecules are all working at the same time to try all the combinations of say potential cryptographic keys?  There are more than a billion molecules in a single drop of water.  So a beaker full of a magic elixir could easily give you a billion times a billion cracks at finding the correct solution.  And the idea is to have all those molecules each try a unique solution at the same time.

Various people have suggested it is possible to mix up special chemicals, say customized DNA, and get them to do just that.  Each molecule would be different so it would test a different possible solution.  Then let's say it is possible to set things up so that the molecule that finds the correct solution fluoresces but all the other molecules don't.  It would then be possible to pick just the "correct" molecule out of the soup, examine it, and from there go straight to the correct solution.  Instead of taking forever it might take perhaps an hour or so to set everything up and get the answer.  That's the idea but no one has come close to making it actually work.

The other and quite different approach depends on Quantum Mechanical phenomena called "superposition" and "entanglement".  It is not appropriate for massively parallel problems.  But it is appropriate for a class of problems that regular computers find hard to solve.  Regular computers are carefully designed so that a particular bit is always either a zero (off) or a one (on).  There are no other possibilities as computer design depends on this.

But superposition and entanglement create situations where something called a Qubit is not either zero or one.  It is in some intermediate indeterminate state.  People have figured out how to use this very indeterminacy to solve certain problems that would otherwise be very hard to solve.  This has the potential of allowing "Quantum" computers to solve problems susceptible to this approach much faster than regular computers operating sequentially.

The theory works just fine.  But the most capable Quantum computer that has been actually built so far can only perform calculations involving a few Qubits.  At this point a simulation of such a small a Quantum computer running on a regular sequential computer would probably get the answer faster than the actual Quantum computer would.  If people can figure out how to build Quantum computers that can calculate using hundreds of Qubits then they would have something.

Lacking some kind of surprise breakthrough I don't expect optical computers or Quantum computers (or chemical solutions) to go anywhere in the near future.  There is nothing on the horizon at this point.  But that's the nature of surprise breakthroughs.  They can arrive out of the blue at any time.  Certainly if a surprise breakthrough materialized I would be forced to change my mind.  I think that's unlikely.  And the same thinking also applies to the prospects of seeing a substantial increase in the speed of standard computers any time soon.  In all likelihood it's not going to happen.

So the likeliest eventuality is boring times ahead in this area.  I see exciting times ahead elsewhere, specifically in biology and medicine.  But that's for another day.  In the mean time you can bore all your friends by wowing them with your deep understanding of computer chips starting with "they are actually called Integrated Circuits".  (At least, that's my fantasy, and we all need fantasies.)  And you can throw shade my way if my pessimistic predictions turn out wrong.  That, at least, is something to look forward to.

George H. W. Bush

This is technically not an obituary.  As I write this Mr. Bush is still alive although his health is poor.  And his beloved wife of 73 years, Barbara, has recently passed away.  It is not uncommon for the surviving spouse of a couple who have been close and who have been together for a long time to follow shortly thereafter.  So that's the reason for this post but not the point of it.

A case can be made (and I'm going to make it) that Mr. Bush (unless otherwise indicated I am referring to George H. W. "Bush 41" Bush and not George W. "Bush 43" Bush) had a front row seat to two extremely important inflection points in society.  In one case I am talking about the evolution of the Republican Party.  In the other I am talking about the Middle East.  I will address the political inflection point first.

I did a post on the history of the two main political parties a couple of years ago (see "http://sigma5.blogspot.com/2016/05/a-brief-history-of-political-parites.html").  But that was a "30 thousand foot" overview and focused primarily on the pre-1960 era.  Here I am going to focus on the period from 1960 on and spend most of my time on the Republican party.  But let me start a little earlier.

Both FDR and Harry Truman were wartime Presidents during World War II.  They fought the war from the White House.  But Eisenhauer was a WW II vet and a war hero.  Kennedy was also a vet and a war hero.  Johnson was not a war hero but he too was in uniform during the war.  And so was Nixon. And so was Ford.  The streak was broken by Carter who was a Navy man but not a WW II veteran.

But it resumed with Reagan and continued with Bush.  None of the post-Kennedy occupants of the White House saw combat until we get to Mr. Bush.  He was a fighter pilot who flew from the decks of aircraft carriers in the Pacific theater.  He was also the last World War II generation President.  As a group the World War II generation Presidents racked up 28 years in office.  That's an inflection point but I am going to fold it into my larger discussion of political parties.

If you review the transcripts of the Kennedy/Nixon debates in 1960 you will find that the policy differences are modest.  Generally speaking the Republican party was more fiscally conservative but neither party could accurately be described as spendthrift.  There was a big discussion about which party was more anti-communist but again both parties were very anti-communist.  There was a bigger difference on social safety net issues like Social Security (Medicare and Medicaid did not exist at the time).  But the Republicans had given up on trying to repeal Social Security or even scale it back.  And the issue of civil rights is quite instructive to the modern eye.

A lot of Republicans of the era were very socially progressive.  A lot of Democrats hailed from the "Solid South" and were very reactionary.  Kennedy won and had solid Democratic majorities in both the House and Senate but was completely unsuccessful in advancing any civil rights legislation.  All that changed when he was assassinated.  Johnson was a southerner and a master political manipulator.  He decided he wanted to pass Civil Rights legislation so he did.  HIs key to success was in talking key southern Democrats into not blocking the legislation.  Then he joined other Democrats together with liberal Republicans to pass the legislation.  He used a similar coalition to pass Medicare and Medicaid.

Johnson was followed in 1968 by Nixon.  By modern lights his political agenda looks down right liberal.  He passed Clean Air and Clean Water legislation.  He created the Environmental Protection Agency.  Johnson was considered a spendthrift for passing budgets with deficits that look tiny to modern eyes.  Nixon balanced the budget in one year and ran very small deficits the rest of the time.  This fiscal conservatism may have led to "stagflation", a stagnant economy with a relatively high level of inflation.  The only President since to deliver a balanced budget is Clinton.  He put Federal spending into surplus but George W. Bush immediately reversed that.

Before Nixon got into office in 1968 the Republicans decided to try something new.  Instead or running a moderate like Nixon in '64 they went with the very conservative for the time, Berry Goldwater.  He got pasted.  That was supposed to kill the conservative movement.  As we now know, it didn't.  It just delayed things.  In 1976 the moderate Ford ran against the moderate Carter.  Carter won.  This caused Republicans to take another look at the whole "conservative" thing.  Reagan, a conservative standard bearer, did well in the '76 primaries against Ford.  This was surprising because technically Ford was an incumbent.  And this sets us up for the showdown of '80.

In 1980 Mr. Bush had a resume to die for.  As mentioned before he was a "war hero" WW II vet.  He also had tons of experience both as an elected official and as a government bureaucrat.  So he had an extremely solid record to run on.  He had served in the House for two and a half terms.  He left his House seat early to become the Ambassador to the United Nations.  From there he moved on to chair the Republican National Committee, serve as Envoy to China before we had an Ambassador, and as director of the Central Intelligence Agency.  These are all high profile governmental positions with a substantial political component.  They showed him to be a committed Republican who knew how to win elections but who also had a high degree of bureaucratic and diplomatic skill.  What better resume could you ask for?

He ran as a moderate Republican and got trounced in the primaries by Reagan.  Reagan knew how to win elections.  But he was well known as a "hands off" administrator who was good at the big picture but poor with the details.  The primary season told Bush in no uncertain terms that he was out of step with the modern Republican voter.  He still had ambitions so he accepted the number two slot and was a loyal Vice President to Reagan for 8 years.  And his gamble paid off.  He secured the Republican nomination in '88 and went on to win the election.

But he had a big problem.  He was still a moderate and frankly didn't understand how conservatives thought.  So he brought in the former governor of New Hampshire and a doctrinaire conservative, John Sununu, to run the Whitehouse staff and did whatever Sununu told him to do.  But his heart wasn't in it.  This resulted in a presidency with a muddled agenda (something about "a thousand points of light" that to this day no one has ever been able to figure out).  And it was obvious to everyone he was faking it.  So conservatives didn't really trust him.  And that let a canny pol from Arkansas named Bill Clinton beat him in '92.  This defeat led Republicans to the conclusion that moderation was for losers.  Since then they have never looked back.

At about this time a canny operator named Newt Gingrich figured out there was a lot of money out there.  A lot of very rich people are very conservative and they are willing to spend a lot of money if they think they can get the results they desire.  So starting in the late '80s Gingrich made the rounds and raised a lot of money.  And he invested for the long run.  He put the money into political infrastructure.  He funded think tanks to come up with slogans and position papers.  He put together schools to teach people how to run campaigns.  He put together schools to teach candidates how to run and win.  He put together groups to find candidates who could front a modern campaign.  They had to look good on TV and know how to stay on message.

Democrats did well in '92 but Gingrich was ready in '94.  By then all this machinery he had put in place was up and running.  Republicans fielded good looking candidates with messages tailored for the TV era.  He even created a national theme, "the contract for America".  It consisted of a bunch of poll tested slogans.  Most of them (i.e. a "balanced budget" constitutional amendment) were bad ideas in reality.  But he didn't promise to implement them.  He just promised that his candidates supported them.  And it worked.  A lot of Republicans won off year elections.  They didn't actually implement anything but they talked about it a lot.

And at the same time conservative talk radio emerged.  This later morphed into the Fox News TV network, innumerable blog posts and web sites, etc.  All this provided a fan base that consistently supported conservative ideas and candidates.  And the whole thing was based on messaging and not actual results.  Mr. Bush was someone who was good at getting results but not so good at messaging.  He was also grounded in the real world with all the complexities, restrictions, frustrations, and inconveniences, that entails.  Catchy slogans win campaigns.  Nuanced arguments lose them.  Mr. Bush was not the last moderate Republican to be his party's standard bearer.  That honor goes to another World War II veteran and war hero Bob Dole.  But Dole also lost to Clinton in '96 and that was that.

Now let me move on to Mr. Bush and the Middle East.  One of the things that caused Carter to lose the '80 election was the Iranian revolution.  And specifically when the revolutionary government kidnapped all of our Embassy staff.  Carter made some bad moves (her should have immediately pushed back at Iran, hard) and had some bad luck (a rescue operation was botched).  Reagan capitalized on this.  So did Saddam Hussein.

In an attempt to make Iraq the preeminent Arab power he invaded Iran.  (Iran is Persian, not Arab.)  This resulted in a war that lasted nearly a decade and did great harm to both countries.  Iran was by far the larger country.  It had substantially more land area, a much greater population, and a much larger economy.  It should have rolled over Iraq with little trouble.  But the revolution had wiped out the Iranian military leadership.  The "human wave" and other extremely primitive tactics employed by Iranian religious leaders allowed Iraq to just barely hang on while costing Iran dearly.  Eventually both sides gave the enterprise up as a bad idea and signed a UN brokered truce.

But this left Iraq in bad shape.  It had essentially bankrupted itself in it's ill fated war with Iran.  In 1990 Saddam decided the solution to this problem was to invade Kuwait.  Kuwait was the opposite of Iran.  It was a small country in size and population but it had a whole lot of oil.  Militarily, this worked out very well in the short run.  The Iraqi army, now battle tested from the Iran war, rolled in and rolled over Kuwait in the blink of an eye.  Bush's initial response was "not our problem".  But he was quickly convinced that he had to act decisively.  And to his credit once the decision was made he did a bang up job.

He first assembled a coalition.  It included the U.S. and its traditional allies.  But it also included a substantial number of Arab countries.  Outside of Iraq, this was one of the least controversial wars.  Everybody was on board with the idea that we were the good guys and that Iraq was the bad guy.  The military offensive was well planned and a large careful buildup took place.  When combat commenced it was a smashing success.  It is generally referred to as "Operation Desert Storm" but it could also be called "the hundred hour war" because that's how long the active phase of the war lasted.

This event has almost completely disappeared from view so let me spend a little more time with it.  It featured some singular characteristics.  The first one is the one I have already noted.  It was a coalition effort.  An extremely wide assortment of countries signed up.  Efforts have been made to duplicate this since in Afghanistan (modest success), Iraq (failure), Libya (again, modest success) and elsewhere.  But Bush is the last US President to actually pull it off.

During the run up to the war I got a map of the region.  To my untutored eye the obvious strategy was what is called a flanking maneuver.  This is where you go around one or the other end of the other guy's army.  To the west of Kuwait is this giant desert.  It seemed obvious to use it to get around to the back of the Iraqi army (which by then was in Kuwait), cut them off from resupply from Iraq, and then attack them from the rear.

The US and allied forces achieved tactical surprise by conning the Iraqis into believing they would do something else, something quite a bit harder militarily to pull off.  The Iraqis fell for it and were completely surprised when the sweep through the desert to their rear took place.  Of course it almost didn't matter.  The US and allied forces were so effective that they almost completely destroyed the Iraqi forces arrayed in front of them even though this was technically a feint.

The other very impressive achievement was how happy all the allies were.  Every force from each part of the world was given a role in the war.  This let them shine.  Each country had no problem making their own forces look good.  So at the end of the war all of the allies were happy with how things came out and how they had been treated.  It was a masterful diplomatic performance.

Unfortunately, there were other not so positive outcomes.  This war featured some very large tank battles.  And what these battled did was what Pearl Harbor did to battleships.  It made it very apparent that the day of the tank was past.  The US and allied tanks did fine but that was because they had all this support from other units.  Pretty much every tank the Iraqis had, and they had a lot, was destroyed.

But only a few of them were destroyed by tank on tank combat.  Airplanes dropping smart bombs turned out to be extremely effective.  As did various shoulder mounted anti-tank weapons.  As did several other weapons.  A Predator drone mounting a Hellfire missile is a great anti-tank weapon.  And the drone/missile combination is much cheaper.  And the tank is ineffective at dealing with drones and missiles.  Nothing has happened in the more than 25 years that have now passed to change this calculus.  But US taxpayers are still buying new tanks for fantastic amounts of money because of pork barrel politics.

The main problem with this war is that it didn't actually settle much of anything.  The old government went back into power in Kuwait and returned to its old ways.  Saddam hung on in Iraq and stuck to his old ways.  And pretty much nothing changed anywhere else in the Arab world as a result of this war.  And one reason for this is something that Bush botched.  And it's something that is often distorted by partisans who discuss it.

As I said, the US and its allies succeeded in flanking the Iraqis.  That means that at hour 100 US forces were in control of the border between Kuwait and Iraq.  From there they could have pivoted and gone into Bagdad, the capital of Iraq.  This is the alternative that is repeatedly brought up and discussed ad nauseum.  Doing so would have made our Arab partners very angry as we promised that our mission was to eject Iraq from Kuwait and not regime change in Iraq.  And we now know what happened when we did go to Bagdad later.  The problem with only discussing this alternative is that it ignores other alternatives.

Once the US military was established and secure in the Iraqi army's rear a decision was made.  That decision was to allow unarmed Iraqi soldiers to return to Iraq unmolested.  They had to leave their equipment behand but they did not risk death or internment by heading for home.  This meant that Saddam lost a lot of equipment but his personnel losses were far smaller than they could have been.  Iraqi soldiers retuned in numbers sufficient to reconstitute the Iraqi military, a key component in Saddam's power structure.  We could have instead rounded up all of those Iraqi soldiers and put them in POW camps for six months or a year but we didn't.

The other decision Bush botched was his failure to institute a no-fly zone over Iraq after the ceasefire.  Saddam's grasp on the reins of power was very fragile in the immediate aftermath of the Kuwait fiasco.  But with his soldiers and his ability to overfly Iraq with jet planes and helicopters he was able to put down the resistance to his regime and retain power.

It is important to understand that there are three major sub-populations in Iraq.  There are Kurds in the North.  There are Shiites in the East (along the Iranian border) and there are Sunnis in the West (along the Syrian border).  Saddam was a Sunni but the largest sub-population were the Shiites.  So he represented a minority government.

As soon as the outcome was obvious the Kurds and the Shiites rose up in revolt.  (They did this in part because we encouraged them to do so in the run up to active combat.)  Saddam was able to put both down using air power.  The US could have bottled the Iraqi army up in Kuwait and enforced a no-fly zone.  If it had it is unlikely that Saddam would have been able to put both factions down.  Most likely he would have been able to put neither down.  Meanwhile, we could have maintained a position of neutrality.  "These revolts are an internal Iraqi matter."

The situation in Iraq quickly fell apart after the end of active combat and this substantially weakened Bush in a manner similar to what had happened to Carter a decade earlier.  And we are living with the international consequences if Bush's actions internationally just as we are dealing with Bush's political failure domestically.  The Republican party has continued to move further and further to the right.  It has also moved further and further away from facts and reality.  But the machine Gingrich created is so effective at delivering political victories anyhow that there is literally no pressure within the GOP to move to more moderate and reasoned positions.

Similarly, the Middle East has continued to deteriorate.  We don't know what would have happened if Saddam's regime had tumbled in 1990.  We certainly wouldn't have had the disastrous war in Iraq that started in 2003 and continues to this day.  Many people believe that the real reason George W. Bush went into Iraq was to prove he could fix what his father had screwed up more than a decade earlier.  Certainly no one has succeeded in assembling and managing a coalition like the one Mr. Bush assembled.  Every subsequent coalition is measured against it and inevitably found wanting.

The 2003 Iraq war has cost the US fantastic amounts of blood and treasure directly.  But our continued involvement has also meant that other options and initiatives have either been impossible or far more costly than they otherwise would have been.  So the Middle East continues to be an extremely unstable part of the world that seems most effective at destroying the dreams of those who live there, those who engage with it, and those who would like to have nothing to do with it but find they can't.  There is an old story from the world of business that ends with "the promotion of the uninvolved".  The big winners in the Middle East seem to be countries like China who have been for the most part uninvolved.  Everybody else has to a greater or lesser extent been a loser.