Monthly Archives: March 2007

D-Wave Quantum Computer

D-Wave claims to have the first commercially viable quantum computer. If it really works as advertised the world is in for tremendous disruption because it will make it possible to almost instantly break the largest encryption keys used for the secure transmission of financial data electronically.

On the other hand, it would also make problems such as weather forecasting and protein folding modeling trivial, so the potential for new medicines and cures for many ailments is a positive side of the coin. It would also make new encryption schemes possible.

Lithium Iron-Disulfide Cells Non-Rechargeable?

Those of you familiar with lithium ion rechargeable batteries may wonder how these new lithium AA batteries work given that common rechargeable lithium batteries have a nominal voltage of 3 volts or greater depending upon chemistry.

The rechargeable lithium cells are usually lithium manganese. Lithium iron disulfide cells are a nominal 1.5 volt cell. These are sold as a higher capacity replacement for alkaline batteries. These batteries are mostly primary cells (non-rechargeable) but there are some versions that are rechargeable, however I do not know if there are any in actual production.

There are experimental high temperature versions of lithium iron disulfide cells that are being used in electric vehicles. These might be workable for commercial vehicles that are always operating but to keep a battery at the required temperatures (around 350 centigrade) while idle would be wasteful and consumers aren’t going to wait for their car battery to warm up before they drive somewhere. There is at least one company that has a ambient temperature rechargeable lithium iron disulfide cell with patents pending.

I’ve seen numerous references on the web to secondary cells but I have yet to find anyone actually selling a rechargeable lithium iron disulfide cell. The potential advantage of such a cell, in terms of power to weight ratio, would be substantial.

I’ve tried to find information on the web on exactly what it is that makes this particular chemistry non-rechargeable and what it is that does make the rechargeable varieties rechargeable and I’ve found nothing. So if you happen to know, please leave a comment. Any good references would be appreciated.

Moore’s Law and uProcessor Technology

For many years Moore’s law which held that the most economic per unit transistor density on an integrated circuit would double every two years held true. In fact, for much of that time it doubled every 18 months. Note that this is the most economic per transistor not the maximum physically possible.

Recently, Moore’s law has stalled. You may have noticed there hasn’t been a noticeable increase in CPU speeds for the last year or so. Manufacturers, unable to economically scale CPU speeds, have gone to multiple core CPU’s.

IBM has promised an 80 core multi-core CPU within five years. Parallel processing has it’s advantages and limitations. The human brain relies on massive parallel processing to overcome the speed limitations of individual neurons and when you consider the huge amount of information the human brain processes, it does quite well.

However, not all tasks lend themselves to parallel processing and those that do require special programming. The human brain gets around this problem by being largely self-programming. That is, neural nets self-train and essentially wire themselves and adjust weightings of individual connections to produce the right results.

So far we haven’t really got this capability in silicon except for some crude neural network chips that attempt to emulate (poorly) neurons and only a very small number of them at that.

For the foreseeable future, parallel processing computers will need to be programmed specifically to use those parallel processors. Some tasks, like encryption key breaking, weather prediction, graphics rendering, shaped charge explosives design, protein folding problems, many of these tasks do lend themselves well to parallel computing, but many other tasks require an intermediate answer to be obtained before the next step can proceed and these tasks do not lend themselves well to parallel processing. These tasks require a single instruction execution unit with a faster clock speed to gain performance.

Heat has become the limiting factor in increasing CPU clock speeds. For years, making components smaller allowed faster speeds because power was dissipated primarily during switching, so the faster transistors switched on or off, the more heat was lost.

As the size of the transistors were reduced, a point was reached where the gates of the transistors became so small that the leakage current through the gate became the predominate source of heat and shrinking components further no longer allowed faster operational speeds.

About 80% of the dissipated power comes from this gate leakage current with CPU’s made with current 65 nanometer line width technology. The gate insulator on these transistors is just five atoms wide.

Intel will be coming out with new CPU’s later this year based upon 45 nanometer line width technology. To address the problem of gate leaking, Intel will be substituting a compound made with hafnium for the current silicon dioxide gate insulator. In addition they are using a metal other than silicon (but they aren’t specific) for the gate structure. Combined, these two things will greatly reduce gate leakage and thus power demands and will allow faster speeds as a result of the reduced heat production.

Interestingly, IBM is also coming out with a new hafnium based gate insulating material for their transition to 45nm design line processors. It seems difficult to believe that Intel and IBM came up with the same solution independently. They announced this development independently on the same day, January 26, 2007, as competing developments. They also will be replacing the polysilicon gate with another metal compound.

Both Intel and IBM have working 45nm processor prototypes running Vista, MacOS and others to demonstrate the functionality of this technology.

AMD is taking a different approach although they may ultimately incorporate hafnium based gate insulators in later 45nm production. IBM and AMD are required to share some information as part of a former legal settlement.

AMD is experimenting with making the transistor gates out of nickel rather than silicon. This allows a thicker gate insulator to be used and still obtain the same control over current flow through the gate.

AMD is also experimenting with “strained silicon” gates. They embed a certain number of germanium atoms within the silicon lattice to stretch it and force the atoms to be farther apart. This allows electronics to move more freely resulting in greater conductivity, higher drive currents, and thus results in faster speeds, up to 20-25% faster. This work is being done in conjunction with IBM.

AMD is also experimenting with adding a silicon on insulator layer that reduces leaking by eliminating stray electron carriers from the chip.

Lastly, AMD is looking into various multi-gate FET transistors that may have some advantages over conventional single gate IGFET’s.

It appears that, although Moore’s law took a temporary break, it is back on track at least for another decade or so. Ultimately these new technologies are expected to also enable a move to 32nm and then later 24nm line width designs. Maybe then we can have accurate weather forecasts.

Abiotic Oil

I hate to harp on this subject because I really feel that for environmental reasons, we do need to shift from hydrocarbon fuels to clean and sustainable sources of energy.

However, the oil companies are doing everything in their power to suppress that transition and keeping the price of oil artificially high through various means such as wars in oil producing countries and pushing the “peak oil” hype.

Since the beginning there has been debate with respect to whether oil is of biological origin or not. Most geologists in the United States seem to be of the opinion that oil is of biological origin.

To anyone with any science knowledge, you know that biological entities do not create or destroy elements. You also know that hydrocarbons are compromised of hydrogen and carbon. All of the hydrocarbons that exist came from hydrogen and carbon that are primordial, whether or not they were cycled through biotic systems.

We also know from lab experiments that given carbon, water, and a few other ingredients present in the earth’s mantle and subject to the temperature and pressure present in the earth’s mantle that we get a mixture of hydrocarbons that agrees with what we pump out of the ground.

We know the raw ingredients are there. We know that subject to the conditions present in the mantle they combine into oil. So I’m hard pressed to understand the opposition to the abiotic oil theory other than vested economic interests wanting to keep supplies limited and by extension, prices high.

Another asinine argument I have heard is that the abiotic oil theory is based upon the fact that we see hydrocarbons on other planets in space. However, the argument is made, this doesn’t seem to be the case for the inner rocky planets. Understandably this is the case with mercury, it is so hot and so small that it would have had problems hanging onto it’s volatiles.

On Venus, while we may not be able to explore and drill for hydrocarbons, we do know that it has a CO2 atmosphere 100x as dense as Earth’s. Given that Earth’s presently got around 380 parts per million that means we’d need to burn about 30,000x as much hydrocarbons as we have so far to get as much CO2 in our atmosphere as Venus, or in other words plenty of reason to believe there are plenty of hydrocarbons left in the Earth. In short, hydrocarbons aren’t the problem, atmosphere is.

No doubt a portion of that carbon and hydrogen has been recycled through life forms and that’s why we do find oil when we drill into old sedimentary deposits, but that is secondary.

The Russians have proved it, by drilling through granite and basaltic capstone, below any sedimentary deposits, they have struck large quantities of oil and become the worlds second largest oil producer, and for a short while before the Yukos siezure, the worlds largest.

Now similar deposits have been tapped by the Russians in Viet Nam (White Tiger field) and Chinese in North Korea, and by a small company in Utah here in the United States.

Now I’ve got really mixed feelings about all of this because on the one hand, we’re not tapping any more atmospheric sources and we’re polluting those and altering our climate. On the other hand, as long as oil remains so highly profitable the oil companies are going to exert huge political influences and prevent alternative technologies from being implemented, however, I fear that if the price of oil fell to realistic levels people would also be reluctant to develop alternatives. Seems like catch-22 situation.