The popular interpretation of Moore’s Law is that computing power, namely of the CPU, doubles every two years or so. This is then extended to pretty much all aspects of computing such as storage, network transfer speeds and so on. Whilst this interpretation has held up reasonably well in the past 40+ years since the law has coined it’s actually not completely accurate as Moore was actually referring to the number of components that could be integrated into a single package for a minimum cost. Thus the real driver behind Moore’s law isn’t performance, per se, it’s the cost at which we can provide said integrated package. Keeping on track with this law hasn’t been easy but innovations like Intel’s new 14nm process are what have been keeping us on track.
CPUs are created through a process called Photolithography whereby a substrate, typically a silicon wafer, has the transistors etched onto it through a process not unlike developing a photo. The defining characteristic of this process is the minimum size of a feature that the process can etch on the wafer which is usually expressed in terms of nanometers. It was long thought that 22nm would be the limit for semiconductor manufacturing as this process was approaching the physical limitations of the substrates used. However Intel, and many other semiconductor manufacturers, have been developing processes that push past this and today Intel has released in depth information regarding their new 14nm process.
The improvements in the process are pretty much what you’d come to expect from a node improvement of this nature. A reduction in node size typically means that a CPU can be made with more transistors that performs better and uses less power than a similar CPU built on a larger sized node. This is most certainly the case with Intel’s new 14nm fabrication process and, interesting enough, they appear to be ahead of the curve so to speak, with the improvements in this process being slightly ahead of the trend. However the most important factor, at least in respect Moore’s Law, is that they’ve managed to keep reducing the cost per transistor.
One of the biggest cost drivers for CPUs is what’s called the yield of the wafer. Each of these wafers costs a certain amount of money and, depending on how big and complex your CPU is, you can only fit a certain number of them on there. However not all of those CPUs will turn out to be viable and the percentage of usable CPUs is what’s known as the wafer yield. Moving to a new node size typically means that your yield takes a dive which drives up the cost of the CPU significantly. The recently embargoed documents from Intel reveals however that the yield for the 14nm process is rapidly approaching that of the 22nm process which is considered to be Intel’s best yielding process to date. This, plus the increased transistor density that’s possible with the new manufacturing process, is what has led to the price per transistor dropping giving Moore’s law a little more breathing room for the next couple years.
This 14nm process is what will be powering Intel’s new Broadwell set of chips, the first of which is due out later this year. Migrating to this new manufacturing process hasn’t been without its difficulties which is what has led to Intel releasing only a subset of the Broadwell chips later this year, with the rest to come in 2015. Until we get our hands on some of the actual chips there’s no telling just how much of an improvement these will be over their Haswell predecessors but the die shrink alone should see some significant improvements. With the yields fast approaching those of its predecessors they’ll hopefully be quite reasonably priced too, for a new technology at least.
It just goes to show that Moore’s law is proving to be far more robust than anyone could have predicted. Exponential growth functions like that are notoriously unsustainable however it seems every time we come up against another wall that threatens to kill the law off another innovative way to deal with it comes around. Intel has long been at the forefront of keeping Moore’s law alive and it seems like they’ll continue to be its patron saint for a long time to come.
Last week I wrote a post about the Solar Roadways Indiegogo campaign that had been sweeping the media. In it I did a lot of back of the envelope math to come up with some figures that made them seem reasonable based on my assumptions which lead me to the conclusion that they looked feasible with the caveat that I was working with very little information. Still I did a decent amount of research into some of the various components to make sure I was in the same order of magnitude. You’d then think that the venerable Thunderf00t’s takedown video on this project would put me at odds with him but, for the most part, I agree with him although there were a couple of glaring oversights which I feel require some attention.
FIrst off let me start off with the stuff that I agree with. He’s completely correct in the assertion that the tile construction isn’t optimal for road usage and the issues that arise from it are non-trivial. The idea of using LEDs sounds great in principle but as he points out they’re nigh on invisible in broad daylight which would make the road appear unmarked, a worrying prospect.Transporting the energy generated by these panels will also be quite challenging as the current produced by your typical solar panel isn’t conducive to being put directly on the grid. The properties of the road also require further validation as whilst the demonstrations shown by Solar Roadways say they’re up to standard there’s little proof to back up these claims so far. Finally the idea of melting snow seemed plausible to me on first look but I had not run any numbers against that claim so I’d defer to Thunderf00t’s analysis on this one.
However his claims about the glass are off the mark in many cases. Firstly it’s completely possible to make clear glass from recycled colour glass, usually through the use of additives like erbium oxide or manganese oxide. I agree on his point that it’s unlikely that they have the facilities available to them to do this right now however it’s not out of the realm of possibility. Thunderf00t also makes the mistake of taking a single item price of a piece of tempered glass off eBay and then uses that to extrapolate to the astronomical cost for covering all of the roads in the USA with it. In fact tempered glass produced at volume is actually rather cheap, about $7.50 per square meter, when you check out some large scale manufacturers. This makes the cost look far more reasonable than the $20 trillion that was originally quoted.
The same thing can be said for the solar panels, PCBs, LEDs and microcontrollers that are underneath them. Solar panels can be had for the low low price of $0.53 per watt (a grand total of about $30 per panel) and RGB LEDs for about $0.08/each (could have 1000 in each panel for $80). Indeed the cost of the construction of the panels themselves are likely to not be that expensive, especially at volume, however the preparation for the surface and the conduit channel are likely to be more expensive than your traditional road. This is because you’d likely have to do the same amount of site prep work for both of them (you can’t just lay these tiles into dirt) and then the panels themselves would be an incidental cost on top.
Tempered glass is also a lot harder than your regular type of glass, something which Thunderf00t missed in his analysis. It’s true that regular glass has a Mohs hardness of around 5 but tempered glass can be up to 7 or higher, depending on the additives used. Traditional road surfaces have a very similar hardness to that of tempered glass meaning they’d stuffer no more wear than a traditional road surface would. Whether this would mean a degradation in optical quality, and therefore solar efficiency, over time is something I can’t really comment on but the argument of sand and other things wearing away the surface doesn’t really hold up.
All this being said though Thunderf00t hits on the big issues that Solar Roadways has to face in order for their idea to become a reality. Whilst I’m still erring on the side of it being possible I do admit that there are numerous gaps in our knowledge of the product, many of which could quickly lead to it being completely infeasible. Still there’s potential for this idea to work in many areas, like the vast highways throughout Australia, even if some of the more outlandish ideas like melting the snow on them might not work out. It will be interesting to see how Solar Roadways reacts to this as there are numerous questions which can’t go unanswered.